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NCERT Solutions for Class 12 Maths Chapter 3 “Matrices” is an important chapter for students who want to pursue higher mathematics or science. Matrices are used in various fields such as physics, engineering, and computer science to represent data, perform operations on data, and solve complex problems.
The chapter begins by introducing the concept of matrices and its notation. Students will learn about different types of matrices such as square matrices, column matrices, row matrices, and their properties.
NCERT Solutions for Class 12 Maths Chapter 3 also provides detailed explanations and a variety of solved examples on how to perform matrix operations such as addition, subtraction, multiplication, and inverse of matrices. The solutions also cover the properties of these operations, such as commutative, associative, and distributive properties.
Additionally, the solutions offer step-by-step guidance on how to approach different types of problems and help students to develop problem-solving skills.

Download PDF of NCERT Solutions for Class 12 Mathematics Chapter 3 Matrices

Answers of Mathematics NCERT solutions for class 12 Chapter 3 Matrices

 

Exercise 3.1

Question 1:y9 AWdApfH86Pnc2vV1s9XjkBbZrk6KQ 44p8IrheEmlxFh9ILA4Eia5z9UrV1RZPFl3 yUIuT1HjIm5SMMg5lO8RDQOhVIad72l9f RU2KYl3M385C1VO4JgLkLKcekz974VCU

In the matrix ,write:

(i) The order of the matrix (ii) The number of elements,

(iii) Write the elements a13, a21, a33, a24, a23

Answer

In the given matrix, the number of rows is 3 and the number of columns is 4. Therefore, the order of the matrix is 3 ×4.

Since the order of the matrix is 3 × 4, there are 3 × 4 = 12 elements in it.

(iii) a13 = 19, a21 = 35, a33 = −5, a24 = 12, a23=

*Question 2:

If a matrix has 24 elements, what are the possible order it can have? What, if it has 13 elements?

Answer

We know that if a matrix is of the order m × n, it has mn elements. Thus, to find all the possible orders of a matrix having 24 elements, we have to find all the ordered pairs of natural numbers whose product is 24.

The ordered pairs are: (1, 24), (24, 1), (2, 12), (12, 2), (3, 8), (8, 3), (4, 6), and(6, 4)

Hence, the possible orders of a matrix having 24 elements are: 1 × 24, 24 × 1, 2 × 12, 12 × 2, 3 × 8, 8 × 3, 4 × 6, and 6 × 4

(1, 13) and (13, 1) are the ordered pairs of natural numbers whose product is 13. Hence, the possible orders of a matrix having 13 elements are 1 × 13 and 13 × 1.

Question 3:

If a matrix has 18 elements, what are the possible orders it can have? What, if it has 5 elements?

Answer

We know that if a matrix is of the order m × n, it has mn elements.
Thus, to find all the possible orders of a matrix having 18 elements, we have to find all the ordered pairs of natural numbers whose product is 18.

The ordered pairs are: (1, 18), (18, 1), (2, 9), (9, 2), (3, 6,), and (6, 3) Hence, the possible orders of a matrix having 18 elements are:

1 × 18, 18 × 1, 2 × 9, 9 × 2, 3 × 6, and 6 × 3

(1, 5) and (5, 1) are the ordered pairs of natural numbers whose product is 5. Hence, the possible orders of a matrix having 5 elements are 1 × 5 and 5 × 1.

Question 5:

Construct a 3 × 4 matrix, whose elements are given by

(i)

(ii)zbHsD1raJksZ6QnUuZEfNBzU0qcBqeQO SV1s1

Answer

In general, a 3 × 4 matrix is given by

CqNxnfneMZCL7pEp9S0x51zOHpAsn 4Z Ct yOxvQJOjGqsDDYd3nagfOl4JpGjTS88JdnJBsatODROnyKVzPYVjWQV3ypAPdcmqUqfu3 AFyj1 a wJ4Ns qeXspWm8vGmb5qk

(i)4ZS7KyjFdHqJW3B2gwEaTW0lSy7MULDRCamjC1omJtLj9plKK9lbX5qd7xAw ppnPXdjXtQsNQYYunLT0H ATYO7YQJigOJvAD41hzaObgt8tPGt TtaM8ZDALwGOcMPzhTEwZI

TmAf9hZlxmpfDOgdtWOTvuNih9Yw55LqxFUS1HC hDvqvVoPykU RQ0Swh348DotPCHZSe0WZH BrkEKJdXHl1IuQQhlzAqrgv4V4lWhciFCIX8aW8 UijVtWYe aUoE3O8lII0

Therefore, the required matrix is

(ii)da 4mwailH1I 6Z1ABPNX IDysZX v5rOWYCU0FnPGVOUIJyeq6eiOnFL Pexd8PyaX WBjx0H 2lVixkTEutadNLF93wkW9e QOwY bQY1E4laOgLVXoV nCRU1vLn7fUlX UY

wNgaQIqRYil42Qn1a d0pPEVFk 5mKMYhgNDuYIudCCfc5HZyyhZsYbJSe7l6tqC1fM55UxfsWYo7iFpcO7tPMv7QPs1guz

Qlt g3 4HyfmepRsiM0scrR0zDbEHW 0qJAPbZB8lB0HpuTgJds ZG8qiHi tSv7SKrin5co99xv6gbSrWHxJhccagQAYAgDAKgTTOedOISzzgdVnNIQsbV5g0R9QXqi R5n3k

Therefore, the required matrix is

Question 6:

Find the value of x, y, and z from the following equation:

(i) (ii) o4mSR2p5I3L1LLcq66jyE4UHAdu59 7pBd9nmq5NWx G0pbi1adCVnWbcc0o3rARFOowlSQmfEOgA3yL blTDoFULakG T0RR0 Hbw5GKJhI gucEdx2ehNsKIA0 wDKIoECXE

(iii)

Answer

(i)

As the given matrices are equal, their corresponding elements are also equal. Comparing the corresponding elements, we get:

x = 1, y = 4, and z = 3

(ii)

As the given matrices are equal, their corresponding elements are also equal. Comparing the corresponding elements, we get:

x + y = 6, xy= 8, 5 + z = 5 Now, 5 + z = 5 ⇒z = 0

We know that:

(xy)2 = (x + y)2 −4xy

⇒(x y)2 = 36 − 32 =4

xy = ±2

Now, when x y = 2 and x + y = 6, we get x = 4 and y = 2,
 When x y = − 2 and x + y = 6, we get x = 2 and y = 4

x = 4, y = 2, and z = 0 or x = 2, y = 4, and z = 0

o4mSR2p5I3L1LLcq66jyE4UHAdu59 7pBd9nmq5NWx G0pbi1adCVnWbcc0o3rARFOowlSQmfEOgA3yL blTDoFULakG T0RR0 Hbw5GKJhI gucEdx2ehNsKIA0 wDKIoECXE

(iii)

As the two matrices are equal, their corresponding elements are also equal. Comparing the corresponding elements, we get:

x + y + z = 9 … (1)

x + z = 5 …(2)

y + z = 7 …(3)

From (1) and (2), we have:

y + 5 = 9

y = 4

Then, from (3), we have: 4 + z = 7

z = 3

x + z = 5

x = 2

x = 2, y = 4, and z = 3

Question 7:

Find the value of a, b, c, and d from the equation:
cWUkY7SfEbhLmfzgz5e96ThthbK46waPZ0ad9p3hOv7Jxu9JnYtEOMwbux K4v7PeP ApN8p6Ly20ZoZNsb WlSM40CBrVuM2CHH9 vHVYXKyKNiKRRaq0zdmuujeJL6OXqERe8

Answer
cWUkY7SfEbhLmfzgz5e96ThthbK46waPZ0ad9p3hOv7Jxu9JnYtEOMwbux K4v7PeP ApN8p6Ly20ZoZNsb WlSM40CBrVuM2CHH9 vHVYXKyKNiKRRaq0zdmuujeJL6OXqERe8

As the two matrices are equal, their corresponding elements are also equal. Comparing the corresponding elements, we get:

ab = −1 … (1) 2a b = 0 …(2)

2a + c = 5 …(3)

3c + d = 13 … (4)

From (2), we have:

b = 2a

Then, from (1), we have:

a− 2a = −1

a =1

b =2

Now, from (3), we have: 2 ×1 + c = 5

c = 3

From (4) we have:

3 ×3 + d = 13

⇒9 + d = 13 ⇒d = 4

a = 1, b = 2, c = 3, and d = 4

Question 8:

is a square matrix,if

  1. m <n
  2. m >n
  3. m = n
  4. None of these 

Answer

The correct answer is C.

It is known that a given matrix is said to be a square matrix,
 if the number of rows is equal to the number of columns.

Therefore,    is a square matrix, if m =n.

Question 9:

Which of the given values of x and y make the following pair of matrices equal

(A)

(B) Not possible to find

(C)

(D)

Answer

The correct answer is B.

It is given that 

Equating the corresponding elements, we get:zhu6d4rgA9ni4K0jwEXGMvMsP9UrkgVDNirAHE8cAUhZfLt7w9lEPV OLliRw92nPKVUturg7Z gPXhfrzzmXkG LKoSQpDVquVnj7DrcBNQxqKg7FWfDwkcQGz6GbUfZI1 NZ4

We find that on comparing the corresponding elements of the two matrices, we get two different values of x, which is not possible.

Hence, it is not possible to find the values of x and y for which the given matrices are equal.

*Question 10:

The number of all possible matrices of order 3 × 3 with each entry 0 or 1 is:

(A) 27

(B) 18

(C) 81

(D) 512 

Answer

The correct answer is D.

The given matrix of the order 3 × 3 has 9 elements and each of these elements can be either 0 or 1.

Now, each of the 9 elements can be filled in two possible ways.

Therefore, by the multiplication principle, the required number of possible matrices is 29

= 512

Exercise 3.2

Question 1:

wvuOVv21qu2S6Nfn33w hoLl 1EY3lxfSJqNRYZ9uNdc BH3TAWEbrj2DamPSJ8rv5x2ylNbfIJnevmVlFpKQOHv3NTkPL5YxBPNKYz

Let 

Find each of the following

(i) A + B (ii) A – B (iii) 3A – C (iv) AB (v) BA

AnswerMPf0xaOKPel0DjfmZaFPmwpuRPRITij4Cw9eGg JfzecMoMqDWs3bIkitPZAe05G4vrRqad77vjtR3EW CtN a1n vNrtdceTE7QN8MNSqj7rxMiHftfhvKulgr Av MJ5HVBzA

(i)

(ii)

(iii)BUCZ9i0bLfE8n3y49GOqWCKZ5I50Uf6ZUMRihx v3b4sXTqdmi3khig RJ5UOEleILoI63rqu8zRTA8s3Zab44YmGo3Lq4c0fJNkU4Q0AZsQieK 04oQ RdlP37 iFwFHvXDD4I

Matrix A has 2 columns. This number is equal to the number of rows in matrix B. Therefore, AB is defined as:

2yXUcBMK EhdoMW6ySKAAO

Matrix B has 2 columns. This number is equal to the number of rows in matrix A. Therefore, BA is definedas:

Question 2:

Compute the following:

  1. uzxbTo8P6Y8xoTog T UHUE3 evBda5rzUZA2IDd SUyYb1ArTcBKijZj6jK6FwA4LroZ8il43 IRkiLQaSIawNdmun4ZyP5J Ef0Lyy7iu3A
  2. reeHgegGpa6Oj1yvNZvqwX7EQTm5T73L5Au1CeErIv1ZxBOzWq0k8rFSdSFVZQaf7Lnqio NUrbtVdbMZwP ThAxmoNl2229CIx4tvhjU cRXvuqxFsKxcNi3f5uKMgQZ7 K P4

XPip0JHkFhLQJT67uaKf3bkonsPKowdrDGWrRItqRrcf oE0gilnowKoSkXL2g1eBnYrqp d2mmYoyyM6jChcezT iceB9C2LZNVqFG6HfJFbiLaJQhUzfS 3CzKhXwGpMGrH8U

    (iii)

    (iv)    

AnswerUdm FgSE32IEQuYh9uMbO6IPQDY4WENZsKfny3 hFCXbT5siLuu2loTnJl4EjwUhYhB eLFx6I9n1y2QED8RYn8K3izVuS3S6RwIs1ZWGVL 4Gy sXf8KP7jMsaZoJ5RgFH0pOc

(i)

(ii)reeHgegGpa6Oj1yvNZvqwX7EQTm5T73L5Au1CeErIv1ZxBOzWq0k8rFSdSFVZQaf7Lnqio NUrbtVdbMZwP ThAxmoNl2229CIx4tvhjU cRXvuqxFsKxcNi3f5uKMgQZ7 K P4

tP64XmVteb7dYKn9p8FDp emPwbJ5J4x617xNb2Y6 9xOkepxzJB a1zvnyHS8 Gz4GFgOrseU9 KMVbv nl3mXF G574ysxAVtpGqERZSRtU0diE

(iii)XPip0JHkFhLQJT67uaKf3bkonsPKowdrDGWrRItqRrcf oE0gilnowKoSkXL2g1eBnYrqp d2mmYoyyM6jChcezT iceB9C2LZNVqFG6HfJFbiLaJQhUzfS 3CzKhXwGpMGrH8U

WVa1rGznXBYVkzC57eEqgzupZ5CQWxwRvxkxbrZDYZFxSkfOFSZzN40S1TFxDtdqy0h7ef8hzxj6mi2Naty3YW5 guA X1VKcU2pkMUiyKVbTjMPqRpdy 93dQX2KThPPmVV OU

(iv)nG nWCwQttu8Zt8 JESCCuujiKINyEDwe1ri0RSQ0IHtrx1o9x9prumNaUi5bXqTN8VBsP JQgWxwyy6RYO9 6K5 HHfQrFzqt7Y41qgJQdh3bJ4Q0hfHgKbyUQ2T2849B1Psz4

Question 3:

Compute the indicated products (i) PaoGxWwRO c1j6HDKhJ2rt40of77w2r2Rw8B46jfUvsQDyRgFnwjE agp5f1gxmV F7GBkBEYDUlvrOiXWtmXpyew68FivQvdtfz0LfGINfGp3G0eOZ 6FFSUPOzHwbynt6TVE0

(ii)

(iii)fsrld8Is1mVwWG44GTD6ehlarpwaNqzAsoH5jrvPqxNyyHASAlERjW14yezsyuTnR8u0h8eocJHWucunxYmboR9p 09XUPF8FurIoO3RiYKh

(iv)

(v)nYJiVWXehO 4whpDuYRD RVOkCVbNiHxL Ni0O5zXmduz8jhVg9F OOAhNwev1THqs3 mxYcyYy jlHZ4w Qz1 ka pSQs3OAgDwfda0iB7aNSE25OPV14p9kYPwQrfzVPlu 3Y

uChTwV8wm3RC4SoBRol3 AtH1nSPtx 52mgprdhXOx2vpm7Cnf76cCg747b50ugl xOhaV iOpF4vcIThsc9mQI8L79 IPuz 5E2zyovESFGOyXNC0Mhyikq57aRMB7RaOi62U

Answer

(i)

(ii)HzN7NQ10dsjlZfFb6GDI7CLACNFazn4WUvFgcXKpFjO5s5 a0dD3wc YTI Sn5gXJEuW8MM0YNkhKyjafRDyKoV256nCVm7eFAL4zF7W37VDjdhiyXk7 E46Zys pDb0ohE0SCA

(iii)fsrld8Is1mVwWG44GTD6ehlarpwaNqzAsoH5jrvPqxNyyHASAlERjW14yezsyuTnR8u0h8eocJHWucunxYmboR9p 09XUPF8FurIoO3RiYKh

8s74aNzzmH5euWjOGPy2mzy6LkShrRVuKG1TmbFYOYK6vkxHkgjukAQClzD32m3tuqzgTyCKQu RUnWhy9a9wb7ht9C9s2L4u X7MozbjCKqJyciJFYQqM6s2XeO0ipzD6c49Sw

(iv)

EybpCxXrlbiCBbmJH2ovl5DIalLO8FgCoMgsisDIKSTi 3CMWqyuWDkqF2aJ44CQP3hoFbPna0u5A14EpKjsY5b8p

(v)nYJiVWXehO 4whpDuYRD RVOkCVbNiHxL Ni0O5zXmduz8jhVg9F OOAhNwev1THqs3 mxYcyYy jlHZ4w Qz1 ka pSQs3OAgDwfda0iB7aNSE25OPV14p9kYPwQrfzVPlu 3Y

7820C56ifg1K0RaTKkzztbcPYsYudMvHgHagdg5 zizBwBos6p1SJ 5IzOtDl7i97x Eq w0o4Co 3FEP6 3CW6WvfMvfpjMPThx J20wCg8604Rr390loRUb83nZLAs9vkk6rQ

(vi)uChTwV8wm3RC4SoBRol3 AtH1nSPtx 52mgprdhXOx2vpm7Cnf76cCg747b50ugl xOhaV iOpF4vcIThsc9mQI8L79 IPuz 5E2zyovESFGOyXNC0Mhyikq57aRMB7RaOi62U

OlZZBJyJ8dJ52pP76M2VAhknuYLeIdy4HGy7YNp5EPIw0T1YPlITRzBLwBijmFaJnGKEf YewN48F0lDLx9TRqmnfEAS5vFI g2qSONkQeJqKknk2 WtcXB24HCbC4L6DStKpA

Question 4:
V dpRDd0bcEvYmfkGsL OnWCmOBMnTYXdvqstb72Ml0lICA0utVJ1Lps00zdJWkp J

If

Compute and . Also, verify that

Answer

OMm1Ctu5usLouPItZGzh9DYxpY20lCQ0G4bJBTi5ZgpmjbXDgSORy0hwHRZJjTd

UqU2dRBUcnPw4r8wVHOHb8lwWYLZhhusRsG19CI qLDc8PtmUTj gDyS1TcxZ6ZdbgYwjuezOYzQHSuMlzJi1eDIEbltekvTiot1eyn2dK aRV33UdG8LgKEc eUcD

Question 5:D9rYjnFgt di80c5bJAu0RmMbwR7aMpUPiJ7Ymours9PXLbslASj3MkfolLXJDdHlxu2A FpPBr6 4NfpevMVyhbWQczwVoeahGDSKYmxAV 5z5W FnZ LRRCYJCZqih59MtzAE
gbjm33tnG55nNYiEqmhm0AM mFHlnE9nBQTuBa81ecsJ U7v0P5lFnF0nFa Dc8MovCZobF

If   , then compute

Answer

rSFHtmb5coLVQ8nK Kb7ErW41z7LF M07W0cSL1VEfbAGTXr0ADDnLpYTHUIAWmkKj6LvWTED88 6esLQ7QJOrfalR10CqDsNS1ptH7dvOjQml 3vVIKB5su5ZWu3hMIIkghHOU

Question 6:

Simplify Fgf1hNgr yyJ3SUV44VMBxVYmaWSNlGSVRQNGeELW0Az ktoQRsnDixl820uRsCbBsQZyKobzgE4ZcZLUKpPR2q8viDet

Answer

Question 7:

Find X and Y, if

J3dxw7PqJIVjj0rcMY9imuSFnruBu4eJ7092PVR9tn1WH78jo4cmv5kpG 0ys8JbfAzCczSAIVOL 3wlo3Hlq4arWiU7Und4WnwvqnDPjhyqh7MTJVO1zFk5l8w vPHt4jL9IQJ3TgIX8zmKX5YX1tZRXO1XVbE

  1. and

(ii)    and

Answer

(i)

Adding equations (1) and (2), we get:JbhdTQKXomOZRBs28KEGWO1qGIz0OVhF SHu48M46DzMyXb

(ii)WVyziAs1eTm eLa7GDcxBMZS7li1XBwBqixnvM8FrhhS0vuDa9grK5bZXWQe1bEkevPBtr4QWmW4cUB6U5QwecwYZjq8472aXvvJAdKK

Multiplying equation (3) with (2), we get:

lexGV4aXMak3dewo2NMUvpCeuELKh vVoovU1fUrJJfFrOdpJGP4h00hk40kTi67thtdmsDPQ1x0NxTGsiR41 nz 0BoBjSEtSBhBUYVY9q 41Dc3OlB5H3YXWY2je5Z0rGOepw

Multiplying equation (4) with (3), we get:
EwEBZ7DgtOeTFGopKBdXuHGZhHl

From (5) and (6), we have:
IRaMP8IlCrUjeQIWat18PfxgXWuDpeEw1iVu1QAVAR eymiegl zFX9k6RA6TF Ykm NbLgfs2k5LXcFX0k94s6i3V59yOde1EqwLvoWXcvie 25qiOgzL rpHp2prjMooH g0

Now,SfMh8kwQ0dYkyV6T SjyFVMmPaFBeTjffI3LOjewuRjfbOfcYwwJCnKj6aYr5MXCnNqbIBx0wUslK6f CyQ u4xjkuh0BotlbqhXvr 3G0x GPkMPJ mzT FqkI2wbwjHRErpg

dKuAdJDLdIBSfucwWcGLXGLFAvsgMfFKdnOFOXvQtduloC727qpoG2jw Wd96eGuqVZ6iD v4EWrrjgGU50AzAPDw Qaz7joy8lJ5mfp QFg61JTTexRvH oMQpmPGmXH3SVrO4

Question 8:

Find X, if                   and C5 yRK9 IJknmZrMPfEJr 1Oxp4OLfYslQ3WolkpQhUN6oHeqintTp0LtU1hMmPAOIxoiu65bHylUwZebD8LQ3gFno3x816WPwH5rNJ6W4ajvhNj 3CDi22bORvIjdyiwjTsDuwMvsZL8 AVX0KKFttBwNTFpctZX7V2CdCkHlLZ5jgGlCDRefd0

Answer

6m ECZMNVU8k nYUnoWTFqcHyIlmp QkkL7yXklWBcuaxjz7oAsh9o7GCbXGpnsBRsbZdPuRR8eNUXttCCXphnL0pYKcAgwS9wOxeq6QH1lPHy fK2daCidO5F aL79vVuIIz5o

Question 9:
Y1Kbwt2fr bvTKcQOD5rKKQHZOnTj2ywKr9T2 1fabAIc5pZ5I3RmC0YzbBdm6HdV1TMUD0sadDvdi b9PO3cpeQJQ7V3R5QJZ7t7Ni5YmHoV82ZUrBEBPhbBTZt57uTSwNshjk

Find x and y, if 

AnswercVMv IZgBZwaKCU4xiYq tqKdm6UVl4Rtv JLaIrjxU14vcmG9 gjJ XKA 1cbTWPjBe7YRKwpPlbl3Iw7aB5JiNFcVsGVUtnigXNdYPP4hFFh9itrLYb6zYqAgJaFDMFXctI2Y

Comparing the corresponding elements of these two matrices, we have:
yPFF544sypodzm8FST X7HhfdMqHOYMfIgiXyMi5UgCnpHkty4tqcdEXWmdGjBlSgzvdiNiPYj Ed9b16jjHt3VFn4Y7cwfw5a022lRT2gqK 1XqRl2gtYGdnSVTEiyLHtlcFiY

x = 3 and y = 3

Question 10:

Solve the equation for x, y, z and t if
f N FGvkap0JqPZ2IekqD02c35U

Answer
8IJMoZTIn xpMZ1MALXoW2JF2zzvghWLpZufS1sC cNt3KkM9GDNp6Ht73EdWdmGpi3W6Iwimno6ePvlsrMUy TfNQaKQMvG2wZIHTLG4YEWmZkIZITeFpipIGK oUb1Eh LLf8

Comparing the corresponding elements of these two matrices, we get:
mELc2Ovmkz4PgzpNN24zaFHPWiUnsUqlbJnyUoT9 e6Z5qxiRa 3A54fA8zeMO76Jiu7oSdgYgpPHB2jo1uviSqADw9CNDLcZgULWRd6DQJAP 9v0WI hMVoojN49vU7apt4gO8

Question 11:

If ,       find values of x and y.TvvT8CIUfcteylqWPS3F7xaBTGW ORb0jeAdvd83CcgF5umP215Bb6QJXvW1DWkDc1MT7rDLfJkSvOXWmO fm5IqfCr9q0nr9 sVWzW8URejBHTUphLOoyfne6ij9nUT3VcB2Bw

AnswermAjybBYPwRF zwg FVV12bivQ1IXL0jk YcszoBs LsZcIQgilLtSqlxtlCVPbjN 3OSEy2cvvVNLVn0kvQTrqI66suqfN5Ew EajREQDShFk2H19FF 9QaQlqKTB6dGFKKcQHY

Comparing the corresponding elements of these two matrices,
we get: 2x y = 10 and 3x + y = 5

Adding these two equations, we have:

5x =15

x =3

Now, 3x + y = 5

y = 5 − 3x

y = 5 − 9 = −4

x = 3 and y = −4

Question 12:

Given ,     find the values of x, y, z and w.GK4yCExQecef1NxkLFmbNBWqK37v5Tjri6pNy5 zLRcX6KEErG86Kf9zg6TrUb9 GmqypKBy r9AUR1BdY ANBYKn7TWBzDOBNECt8 B4ifScoKkC80bYzWtg lH8xrG4YzH1X10reqCvBCTQepQS7qPwkDrzWeyqJHUCdSMv5vS9GCf7OemO UyUzTaLfw

Answer

Comparing the corresponding elements of these two matrices, we get:

*Question 13:
90G 84uRdgvfueNhXiXLl7qEl3XBUUvOOyq S2VF3Zdg52xi6MUsBD 5BTj2yr41XibMWrCxhXVe lnfS7Iicbi3PwIcOHAjDwc

If       , show that . 

Answer

9eTT0mCO63GFvhTtmsvlx lgRGctbjjExodSuw2tr4KsA1eZZ07dPm9eqt1whZQeXeIvkLK6oyI4fEUtGT Q9bo0EUxqiVS 30ueg0NjHHoqqIV fLRb4jn0 qW0tRT0PlbE0Ek

Question 14:

Show that

(i)

(ii)mG8sA FkNE9wngFM kz2VtzKHhs ILweW 5JeML vqfqI K1z9mEg7Akyp7HTJP Rz WwR 3J78ErET1quzAUYL9NU5ImLkeAST zPdONfjkBLLuoWvBOXeKzBzniko jRKVT0

Answer

(i)YqRygPS3QH2lCMpW6vwOZsIrg1ekHrRNFVnmnxpkYh44M50Cqo8Yf9sMzfzgRgwLt3Qj FFnM8dbVmFN0RocnxOUUmwlmaLicxDaZPZmablKDBs0u7

(ii)91ZHZggRPJr7PQdeSM0S5YHBZ5sOCZTVqJIPe3e2IaNc2VOLDbVghZ7eviRjvxEPdG4nNuuF9P6ZSNLzE b6Fez9mvKLFpy51OJcdq7JQh a ypfjXKzN3VHIbGlscC67Ey9nd4

o6KFsAv50zMPwXDFUUTyCD3ArsqV wUEuT8OXc2pS5UTDsL8oizd5wy uJ821De2xeQ9x L9dFooK2V3ie WAFW PyGpJobeqL6K6LUwF 6RkvkJfhZLjHnGEoavMhZzUgU2ZrU

Question 15:
7JxHdvhyNgv8PI6SDVH7mUiymczyXsjD9RDQafnDsO65ynv1tGr6 6TLz2oGp G71mSQgEGbSTXd0Syopa7IUy1IaoJf1Qn7eU33CXPnq18L235LmJRv977hMGX2RZb3eVKL9NU

Find RwIq9al1cn6sj1eRG3AYUsNf4atxooBqb8PjLvmV5 Q5B6K2Km3PeIn QG4FhvB3 if

Answer

We have A2 = A × A

VIEj4vCkqfkGJTBqRBOg7CSiLIuqDDFzLsd4RbfkBbpNWgz5UibZjgLDwoZx

qfS9ZdnMVnwJeRDjlCbWAXYnDcDTthZKysibzUO3iE4OKFbTrpX0kbZO1VC8c3DRwdghsOQNrn3XwBzxbcPHMfPH0SWHXhfvId6aq PVACnVXO6WsEwJC6A ccsYTrC2S k tkI

Question 16:BB B5v

If , prove that 2HD4dgqjhw0XefJxIXiyPB5gnMA1qn2 xNnHHsRYMPa8PctR6EOfejHZVPeCTBS8yEHAewZ54OGzBCqz6idtEgsBHsaRvgChFtU2OT7LQS0m

AnswerJUGkueulbKWlpZWL8RzkM DuPqXRquaEEVac0hX3g3e4dwpy2T8T qNnreeLSm5jYs9LKPulwPFy3bCL2msrotsOp0syqqXUw5o2VZ3rfl4 DlEetViBzMZnPdGlqdTl7PbkJlQ

Pk19 zjIQahE5Wgy8lMzVwsPGgjHeVvEvpR ZrR9o5oA1Icf7w ucOz2WHLDvkKPg0KH1J6CWEPN9MAgD2X

*Question 17:zC2iBwzWXL1vWheUr 6xaxZ1Mebwacyy3O3O9Xk8 pRH8 heSG5np28kXy nKiovdev eEz Kle61JL6ZdbJjSNR0T29OKM7RywmWpnpaEJ2k3kQe5Xw2OOUEAYWEuWLlqzao94

If and     , find k so that 1u 3C1 PcCRpm KhJrqc

Answerq4wMCbuLrKTpUXyzk58CtpY6 OGYQxOCj7RD6G4iBLwg1dkhjRsAtwCI vh dX3EDG7YVmLBv7z3ZXH1pgHcY1cbIz7RLq6lW1hxQmdUMm kWF6EjkXVsuS5jKl CJ2wpM3RXY

Comparing the corresponding elements, we have:

Thus, the value of k is 1.

*Question 18:
CKRmPjycE2gm9xNWWJqgrvwmsBKrL31dXvhnBafWh3QLmPsJLs 7lyrAhnkWGzC GGl8SYI8clAYTME 5R1PFGui5YT8S7 2KzBt MWMBHzn 03X1r9aQ1QaCeovif5CMaFMuU

If       and I is the identity matrix of order 2, show that

Qe2blObNGnGg6CGomVGITtOw9 TewS655UhDooNHdH5CGjytgimeGy5WAr9J3m6dbMoJftN8Q5VDbAqoVNIaAyZ6AlCsC98umkJCK9wxqkrDKXe6h 2cHRb9d4TN8Ngsfs5XnY

Answer

wgc6P99EXoG Sjs5D9XTHFEHQv eBiEtKruio71CedUJlzNquShRR F8Bf54YrpILBqEZ6fFtDLW6gXTOzoPja4PVeLG3nYo7yXa67DO O0J9SMbAcFDhWSpF54fd5s9XjQcV8

v2uHRDFKDHPsVrFvFwN9TBHvmG4 n6o 34RKKfSdeqXb6cnyH6gt2ddtXKfRkevwhJVySmPaKreVc57r kcROkBriXfBo6SLiV25NDwP yElAh9se4HS2IwaVpQXRTCqwhMYEw

uncdCWTOD8gqn wQ2xQU1y8uwSYjZxGWesYTy JaOMAa0LaPJbaZ6fkJQ3dtN4DNAObQi5Qpf HLAjnqxd

Question 19:

A trust fund has Rs 30,000 that must be invested in two different types of bonds. The first bond pays 5% interest per year, and the second bond pays 7% interest per year. Using matrix multiplication, determine how to divide Rs 30,000 among the two types of bonds. If the trust fund must obtain an annual total interest of:

(a) Rs 1,800 (b) Rs 2,000

Answer

(a) Let Rsx be invested in the first bond. Then, the sum of money invested in the second bond will be Rs (30000 −x).

It is given that the first bond pays 5% interest per year and the second bond pays 7% interest per year.

Therefore, in order to obtain an annual total interest of Rs 1800, we have:

UmoF0kePYyDxDqlrIwu nIVbXEkFYBcdIKfTbC4RmDsjNixvS2XCdFAbP

Thus, in order to obtain an annual total interest of Rs 1800, the trust fund should invest Rs 15000 in the first bond and the remaining Rs 15000 in the second bond.

(b) Let Rs x be invested in the first bond. Then, the sum of money invested in the second bond will be Rs (30000 −x).

Therefore, in order to obtain an annual total interest of Rs 2000, we have:

xoHvFBFUg1CCVs ZWDPnKlQF3J 80otB2kcDl1xAkU9HQ1RMdtbpVhsa5t6v55vzQXLuonz0qK59gSCh0u9oJwliV1nyDyD6sjmJ

Thus, in order to obtain an annual total interest of Rs 2000, the trust fund should invest Rs 5000 in the first bond and the remaining Rs 25000 in the second bond.

Question 20:

The bookshop of a particular school has 10 dozen chemistry books, 8 dozen physics books, 10 dozen economics books. Their selling prices are Rs 80, Rs 60 and Rs 40 each respectively. Find the total amount the bookshop will receive from selling all the books using matrix algebra.

Answer

The bookshop has 10 dozen chemistry books, 8 dozen physics books, and 10 dozen economics books.

The selling prices of a chemistry book, a physics book, and an economics book are respectively given as Rs 80, Rs 60, and Rs 40.

The total amount of money that will be received from the sale of all these books can be represented in the form of a matrix as:

Thus, the bookshop will receive Rs 20160 from the sale of all these books.

Question 21:

Assume X, Y, Z, W and P are matrices of order CHjM1VPrJ8KYg8UKM I0edg7w7LwvfytHH5d0iA2P26izKkLzWM nVxKFy5IEssUtwu6z37py3ViV Ta8iDnwH asCZmnSbdh44WSn9C PIBoZRlYqsZIQeNk6sN Oa6n1fPFXM, and gqqZgDq00PDZEtSH9YoLFL3UXLcAXRqRKgN7B TdWOUxuqBq bOju0cO8ZZtw A9gd44hXl85k AMAIsCOn3zAKO Jf7OgLuCtaF8kHFZsCsPIcvTAr FEK4Gz0SHoof HJZporespectively. The restriction on n, k and p so that o3c3JxsUKxZ lK74kvO8Q8XpM3DWm1l05sMwq6ATHi59 YAMIqG 5Ul6EqIX6tJ1uNIhGvUFSmrOhQ q1Zdwill be defined are:

  1. k = 3, p =n
  2. k is arbitrary, p =2
  3. p is arbitrary, k =3
  4. k = 2, p = 3

Answer

Matrices P and Y are of the orders p × k and 3 × k respectively.

Therefore, matrix PY will be defined if k = 3. Consequently, PY will be of the order p × k. Matrices W and Y are of the orders n × 3 and 3 × k respectively.

Since the number of columns in W is equal to the number of rows in Y, matrix WY is well-defined and is of the order n × k.

Matrices PY and WY can be added only when their orders are the same.

However, PY is of the order p × k and WY is of the order n × k. Therefore, we must have

p = n.

Thus, k = 3 and p = n are the restrictions on n, k, and p so that o3c3JxsUKxZ lK74kvO8Q8XpM3DWm1l05sMwq6ATHi59 YAMIqG 5Ul6EqIX6tJ1uNIhGvUFSmrOhQ q1Zdwill be defined.

Question 22:

Assume X, Y, Z, W and P are matrices of order CHjM1VPrJ8KYg8UKM I0edg7w7LwvfytHH5d0iA2P26izKkLzWM nVxKFy5IEssUtwu6z37py3ViV Ta8iDnwH asCZmnSbdh44WSn9C PIBoZRlYqsZIQeNk6sN Oa6n1fPFXM, and gqqZgDq00PDZEtSH9YoLFL3UXLcAXRqRKgN7B TdWOUxuqBq bOju0cO8ZZtw A9gd44hXl85k AMAIsCOn3zAKO Jf7OgLuCtaF8kHFZsCsPIcvTAr FEK4Gz0SHoof HJZporespectively. If n = p, then the order of the matrixLSq87ryiVKlXbQSOFkEErF MtVy4UWPgXYHCoesk4MT6oITUHauOEQEZbVf5uLln3qsUdbAfHIoGVlBcF1HpRawTUEScFHf9v4hy1VAel9NMR5B0QhwHbCE9LIgkRwSdL05sTIEis

A p × 2 

B 2 × n

C n × 3 

D p × n

Answer

The correct answer is B. Matrix X is of the order 2 × n.

Therefore, matrix 7X is also of the same order.

Matrix Z is of the order 2 × p, i.e., 2 × n [Since n =p] Therefore, matrix 5Z is also of the same order.

Now, both the matrices 7X and 5Z are of the order 2 × n. Thus, matrix 7X − 5Z is well-defined and is of the order 2 × n.

Exercise 3.3

Question 1:

Find the transpose of each of the following matrices:

(i)

Ngcc2lCfsrgOTWFo WNQ4lan 7J9wzD tucw0ZecZ91Aor2k9UbKq9iOcupBFSYC0hOrQwJ8h5xczpXIC43q0yInFVte vzOujvmXkgGSBoCfJtVaB 8JLsdZFL oSSpdJT9ABQ

(ii)

HxBR 1eBHL28EgBJKmfGq5VNXcVEJYCg2TJUDYgEQdWNHQklhvTTNUyq TlevQA JtRqK2Szb6dlO94ZO1cuOvbxEOHPd3RPnc2 tyMmfQLwiybL8jaIlil4X6fWY2Y464EGK3Y

(iii)

AnswerYd 5 7GhsV3bO7iX1 NOPTvIUVcUhQIdSbJDde2Qu1TGQVNPPcm NZSq U6PXmDudR1lBINf2qxK3kfePumLvg4RjOUfxd5 Wg8r8tPh9HMDqBdTTnqJlrHsAU US0MjF83ZUL4

(i)

(ii) OD9le4IsZ PyHJSjOVt SzqzBLNcjjf 9Hqj1EB0tJCeckJAKWAFO98u724q0hIkj0WmM0A1QUpgGjTBPnTCAVhS2LqGWnvCAn

(iii)

Question 2:
96U1H0HBIiX1IGKAMrk3eGgFtVd1EqXVZiXiTuE1hQ2ui5X1XjJUVdB6aXluN0l J2ISsNsBoM3AFuYd WNm0WHi6C5DLXpYgL0fDtCMUCSpvL 9BsKn65J CO285dY1Cauc9oU

If     and         , then verify that

(i)

(ii)

Answer

We have:

lIAp5LHNFn3pI4jkUx8jMy28GOtbxAskCgwCt0Qw9AWpnmf ecsTr7KlMXr miGwCkFBBoI36I

(i)RVENztAWeyjIzCzQgX9JoITSmA0XrzKF26i8DhXmmnp8b9h62nw5UE2fxYGNcEurBbNcVIRBwXnVHfbdd75nh0bbArD8TQy8mMxngkABY7RW DDNn4iapfvK lptVs162SIbQI

(ii)so gjXoMd4xJj3kRjzHwXSD8X 4WZyz5imYVeFjknyZOgtgB8QRgNzij69rOCZnmJabjOiuaeAuz25xZ6UEXlbvHgmbpSWS6Oxeo8MSrj731N 9h75hzhbeD1waiHUg9NnEW Uo

Question 3:

If and   , then verify that nUOCEbwq7xda5mW9tfv9U9LQ8GS0 c6iTmmqljfXYWLmhwr0cXogScLKWsq4K mHPpDJberd9bE61RjMALJSIYShC8LY8cpvusK9GhxiepH5LYR8 Qau

(i)

(ii)

Answer

It is known that Therefore, we have:

UIvO9IIWCuegDfWB2tk4Q90LuMszRT5wDiyc Yj7m6AcMlwNh3uFTK2HPquXeG BxBjGEByZyEIVdyNW9g2BR18FA8Yg4Kjzf VwA 4F6qP

(ii)

Question 4:

If  and   , then find 

Answer

We know that
rGscqnf9kHemZ4BDU9gDmH YwXMx6oWT VaeG9djqPrjnuzcsjTo7T96zUqr2tr0rWVn6C8BgJvoruP

Question 5:

For the matrices A and B, verify that (AB)′ =QaZHCOKAXjBcFMJIQfFPY2de4I3YpmvOyCvksEOnAicEvnuIT5ZbjcRKCfaG028rbJgN3YQ9mon1BTFQR2tKCsiu8emcRUH710i1cfvrUccs0R fdPuiAlUhYhLAaJXiwd5irpQwhere

(i)vfgMCz k46XkqOWyX95zeMmTySYR0w7nIiOcfXYqFp4tQZWmqLhIW1EDl5Uz57kbxAQTM7 6QPIO6z6 Ay4D1rV3ZOqsNUFchvoZfI FbFSmw0sjDg16EdJe1q3HOfBY MQwuIY

(ii)dWIyGvPwXDLYpI29J0MynHVFzmn4sGNIXqyo JncmVsDdacWEABwQGMFynO9GaD5nBJX9FJnQv3L XtLTlheLwEMFtJ7tgLVvVDw6apqQA4u0NXuo

AnswerViNvXpNFOsPTNZS5Axq0DQ3G0J2kgPL6Y C jPJEjeOacGqy8XJ6mRnbRjj3c

(i)

(ii)

*Question 6:
rBwoN7rfFFPZOUT XKq8XW7Ukm Ep7gl9LoHocYxAPIBwAoFLKiA xTFCvE3TNJi69wh TFWq3NXW2x LtZY2n3Mb NTtUd L5GJsphjIJq6LHTanKcWFWskUp Bh14YVKWw54

If (i) , then verify that JrWu ULdNBmHrmGZlHi qLzWBLNy6gJmohKvpqqGOt 3wAF7LiA3Lh8o1cpnTgD4X3oiGnaDkiZedU0bW sferGOYbcjEXWkGv01aydcMn0zPEZimHVXe1XN4nItwDTzh9FZ3m0

F2F hL4N0 ZXH5SoLVyEzbPIzaxvjv OlbBNWHoxYo7hm6eeoCPGemd5x dUnI852xNZE VyUmuja953PGpinHonDVElDl nGTzKDPGBSksJDt52KdyujFTiWm0A5uqf zZc4v8

, then verify that JrWu ULdNBmHrmGZlHi qLzWBLNy6gJmohKvpqqGOt 3wAF7LiA3Lh8o1cpnTgD4X3oiGnaDkiZedU0bW sferGOYbcjEXWkGv01aydcMn0zPEZimHVXe1XN4nItwDTzh9FZ3m0

Answer

(i)

(ii)IIvn0WLjXidfhg ZzeP171vuLqpKi8C5s TCss0EPAZ98fNuOK5jXOZSUQmAEzOOJImLiR8avYbp2PUO4 MlPW2oSruByn M3nXnJr49qT7AYhQKEMFaT1QGNHJjBDO7wfhlNZ0

v1tGKEIzEBJTaZAtRcVYx1fBRZ4z3YPVDlMFvoAmcswaoi51pIl10ibeJ04LEkIyXosuxw3x8xtfhYkZN8Blm1xpbTGjzg5z snuWDmzEawgXtABMLgLmCzbZhaBWpsbdeNyo94

Question 7:
Pdp5 b6L3O7R03GFtHePuS5rXPeG tanx04ave55ESIb6 XOsfvShcPWT

Show that the matrix is a symmetric matrix

rycnD72JWi9kyYnBScrfidzJxovdIaaRteFmep2VqDZLgMKQIxZ1v75ymD66rJYmIPRFa f8xeRWtAOvUTzba5Qur7I7 S 5t0Qay159VaBeEX24uM609sAiU3z RUP0JEGJeFw

Show that the matrix is a skew symmetric matrix

Answer

We have:
s1oQZCepEfVuwkel6aBkyf6b1vkLPqKzFjelfVM6JoDI5E oa7aW1yl7jurOC3l36jsODRV1D6JHmRcn5BoYkRWewCQT kXY7wovS5kZFDWxw NaWb217fSEsktbp2WWPNqE03o

Hence, A is a symmetric matrix.

We have:

zVKl8qnT0OeR 3 Un44mo1eB2yekQM7vX zyrlU9Vq9rI6LJ16snTTYEaC7QnTfQ4w7JARcgwna7hr1KuEz4vgm0bIGBCxuc y4CeeVwjI 3

Hence, A is a skew-symmetric matrix.

*Question 8:

For the matrix , verify that

(i)  is a symmetric matrix

(ii)  is a skew symmetric matrix 

Answer

OnoX5ZWoNInpfC1KCYyC0P4NcgvMbDAuqCHDmKwG5LsB 1Wyjy7bHC62vYUrYjwGWmFG N K

(i)Jctv1h8q7KR 4OSApuRbeBmIe36wMqJ4xA0QVOHayusOblre6ihslLqjnzZ3Oo4VpxilEhH rYn4we28nCGq44HB12f PPYNqNyaMXYV0venEAED2ZE k9ou2Pa54DjlvToqgE4

Ok 9XYpeAFhWm0HjL 0vyp4yQ 1KI7EIGYEGJQBbjYOVf9 r8JcMYc7yIPeV4ZvLMiGiuETh97Bra7IJYor6XJtqRnIU9KRgSjsUdv4qIIL7JOZsizaAd e1EJqEIH1sXz0sybI

Hence,  is a symmetric matrix.

(ii)
oes6mbzGUUUTqGVMLG eHy7oGaoySi1tEaLshLsFxyxP1jqAGo2XVkp9O7Bjyf4wGUyW6Feg7y5Edi8uorUFDwttwpVesOa0XJ1RDGsIofxeYW sYVGZMxG67ZpbRHIR DY9Peo

Hence, is a skew-symmetric matrix.

Question 9:gmFFyBdjInD0IvmwFvO3D2ElNf9u i3sOG8t8t1r O xociFjq98xkCmgae3cVHiTbfuM5GNeP1BDSU45N6iMDhlMa97qmyg97W8fhVuwHO RBFac6lTu5U6Iit5671Sez9OGmo
GDzAl5hUzlUiW3lahS9d0ThgTfDHwHdepOpp8OEOiRaLWkSYBlUJ2AuXEmhQ7fXnl5nnrH9R7RuYNUUT2la9GgUE48rlnA69sEWEF4WTTyD0SAODtucGVzVIQ2j6VctMmCfed3sT4v6do1dDWBpUVrqRSeQ1OdGaMX2CNO5soev QX0rc0PaJ3qr5bFjm3KpRH2Qw5tPMeOfXbb4hNRgjROFnJoV0JWVdv5 Q1dcM6H6LaNnqHt5JrVuYhUt7OUfH zeimDYoNkGNY

Find and where  

AnswergmFFyBdjInD0IvmwFvO3D2ElNf9u i3sOG8t8t1r O xociFjq98xkCmgae3cVHiTbfuM5GNeP1BDSU45N6iMDhlMa97qmyg97W8fhVuwHO RBFac6lTu5U6Iit5671Sez9OGmo

The given matrix is

VaoxQ4xsWDHcL7WAJ0TfPuyWpPeDZeScwBsVZytLfJWJjUMfO3g9shm3kSsUvYz8 f LR5FRF7qkiev3AyHCcbN40AktK3zUb4Tz3IDshPxNMX 65douoT7zOjWiM AGjIQzyBU

Question 10:

Express the following matrices as the sum of a symmetric and a skew symmetric matrix: 

(i) QaCd76FhOTwrPc1 E3DNnIGpnspdZXUizyKji mAfTCQKbZAPbLd z8E0FXKrRGR1EKcJ2qk2 OCIkn1fky

(ii)ecF9w2UByt2oN6we7pQIGK99TjvE3WFM2ZcBeDoIJAB0pLHzhBJBCuzVZS7U5PZQV VAlGY VdDqtEcOVJloJI7RItcc9TEI80ng7cI7mB1UPq775aR434 Ulh0lpzpLBet4k3Y

(iii)B3clvWkfxdvxmA76HIpiy44BPhXjVFJZwPMdrY6Kzicaa2ybaOYvY5Kcou PdUavjL05UmaXNTxXX3onNbit8ncWIzFfA7epIYyt L4ONE4AC7JQRsu14q2Q9DzMgTCh v7A5zg

(iv)wjx82b6NP4nhIhDaXVhVD

AnswerqBjEBlbQJmo8I97ZSTifEGs 7AmtUZ4Pq1dVRa7opTA03rPC 6QyFH0k0 BcS0W14rihqHW7W8V0A7CEkwjEzy0K5bcPd4FjghiOL3UurIbHpaVZD1AhTK9Mfsz2P 4hKlGX91Y

(i)

Thus,                         is a symmetric matrix.

JUYuvaZYOH7pZCxuPRlMTTeui 7biiCSeYnftK8aCb2WznpB0qLRBo28DzA436mO 3iPOUlIOwnxXnabRnk919Yb3Ni3IygP pL0FWDtVXGgsU0my67V8ttqVye2OnnyyQS7u1g

Ib7cWq3iSCRCGZkY5HbOp 4QmXse3YeF4H ZzCqdUjSD dwneT iX8NlJ0vnnBk4nUBnuZ0b7JPeRIjr4RqkozRODJgQXUlhXI2VBBx oJGr477wXFr rLSa oD7MuZmBS91 Y
0G8Ah3Yz74W4V7kGeyILV6mOaMnLjZ2opRcTfp0Po0DqWJ3RGrPBMQjaJZu5K2wAN Ro SUeCVvQ8770nYlsA8QH8b OJ5uK2dIkCumQFbNyI2WBuhk H7tn1 Luc6JHbrsjdWc

Thus, is a skew-symmetric matrix. Representing A as the sum of P and Q:

(ii)fBPs9VqELWDKlanColaiDFWox 50J6vTDxfMIxI7lB0EQ PmK7B6imtue6 9y VzgwmmGTR

Thus, is a symmetric matrix.

Ib7cWq3iSCRCGZkY5HbOp 4QmXse3YeF4H ZzCqdUjSD dwneT iX8NlJ0vnnBk4nUBnuZ0b7JPeRIjr4RqkozRODJgQXUlhXI2VBBx oJGr477wXFr rLSa oD7MuZmBS91 Y

Thus, is a skew-symmetric matrix. Representing A as the sum of P and Q:

aPUURZMdsZ9

YGo7B0T1gS7pl wSw8oIrc8bwoDyO6R0TsArhMT9LRrxIX1zVLIqJtu eKAA6wSaaQg7MKQkrepSboWDAKc vTew7OpRmGna0CutfXLtkpqJ9sTLeCUYc5BOBblUkDwr0QmuZGc

(iii)

fXs7JGGVLSVWh1dn0QfT IEHKcDIMFS8idrB65F7HuhsB4NC XJLDLDovmSfHX

Thus, is a symmetric matrix.

6ojW7IW8gPPNyKf onKzAW8G0yg2enArxPkCFYG5MkuHGoFDdHk8JE7vsn1ZXWYAM9gUgWT6YGbgzvF gWVZDW1kmbyAAWDotlv0QldalI1rLZjoNYWn7r v8 oPSGwotF18uLo
Ib7cWq3iSCRCGZkY5HbOp 4QmXse3YeF4H ZzCqdUjSD dwneT iX8NlJ0vnnBk4nUBnuZ0b7JPeRIjr4RqkozRODJgQXUlhXI2VBBx oJGr477wXFr rLSa oD7MuZmBS91 Y

Thus, is a skew-symmetric matrix.

Representing A as the sum of P and Q:
yaL5HGL2 OC4Uyr wg7WgRDwq luP JJa2bkQ30RkZokpYISyrM2GX2XYJXC2CbVqmvLaZcQpPiBQz2sYh8K29H0e8NAJ15zcrH1j7NzY62kLiXxyEV lME xM5yKd2nE2V I0

Thus, is a symmetric matrix.BNeCRUChvLN uzDs3GOtAr4gyTrBL

Thus, is a skew-symmetric matrix. Representing A as the sum of P and Q:

X3XJzGEnyl1RHw58pfOTUkVXxqZoG5vw WIGxRXSn6G9yRQRjyG5yiAZh3ghwOz7tuaDISU3y4Fev

Question 11:

If A, B are symmetric matrices of same order, then AB BA is a

A. Skew symmetric matrix B. Symmetric matrix

C. Zeromatrix D. Identitymatrix 

Answer

The correct answer is A.

A andB are symmetric matrices, therefore, we have:
jrVzSBNnA

Thus, (AB BA) is a skew-symmetric matrix.

*Question 12:

If ,then , if the value of α isZMPaQRj2iuiWSjxMSCc9M gsPRwFSuBdnmw rlTyHeWZUtoQWOrTtbirbGw8PAnSXJiqXkbdbWb2rccXnNKwhRnyK0WXgweDiG5ejQ8lL3

A.  B.

C. π D.TWvxn4IwRF6BXGphfqgiLuws4PTN1EaY4OzMUORZ0fo 2EsQmyBU4KcT 1e63oA8mGGYOsIfMSPT3UgFFcTv6YLyYqM686If5W2R FJ7C A1X7Kz7AwK9qVtOLXZfy3Cz7jA dQ

Answer

The correct answer is B.

C4sURaA HgCP7q0esYVROr6MkIJIxaxjRv3x1Cng FJS0t0xENe3cZTSsK2JTMHzxALrZJSfJl422Mc C8OxLkBHjnOIOwJ

Comparing the corresponding elements of the two matrices, we have:
LKMve44D w9NaSrJ4k9VVCWWsTgtKBszf9Dz3BlEMsEYS4EXBTgZ

Exercise 3.4

Question 1:

Find the inverse of each of the matrices, if it exists.
4AxZf16QlGrKi25Q zW2wqlOKx2G6ffCsnvXGbdM5sl2kZr2EiCjbeftvJ9pX5VPbS kuI2F9r9fuwYumbBgYy3o6ntpvITf819EMzICpJcV3pI gz8 Faw0HeHk10Xzzyjefvo

Answer
zvws1rJiMfTdTF6hMeJ9WgpnACQmYtBNlJhQpFgAG2mDeCAa4A43jG0A8Erk9UVBlUaoR6IY14mVASuapxF821QJ7b4EabNS4c2UYZ fny3jwA510iJq HKkQKUdVKm7BsAB 0I

We know that A = IA

LzoKo uGERfuPclSK56s0Zq058dSf04n njuq4PKkiZYNMWEi2v9lfy OlHPAjWT1kSb5peCdEXmZvCTFAALhPJti lPG836QCorEcKZEYl0U

Question 2:

Find the inverse of each of the matrices, if it exists.
aI1yAIsFyYvZwMdM3yEeCifInYt2kDztfTKHwLc7BVrfwB 1DaJLfRcj9tY3OnvOg7wyZLznsy6L1f umuDatsTqdCbXhBvLDla 19Ln6avgP0hFhcjPvXwcELLcmiBS5BPU9KM

Answer
ZIb oB5ZJ99cWXrGOoericcpOXZZSim54qd3O5 vyW0i iJZWtn1ZS8 JvY8WIxtFsP7e ezlDAXVahTrJ0dAHIS9Dhzc7aTzqnl50XzGPxbNck1r THAnk8mh9WmZqBJqF URU

We know that A = IA
e73kn7XG83B1vwQIz1ZJTS3BKosbVqWBpfitgD25RJhUX6OvFM9 d7RDzJswG2ZSY

jj5MUw8XSIKrezy iN9jh4MLcmi Hk fuycIwEHpMWdTmGnMzggPcy4vLGpLohpoNq9w3FKbHuFYg4IVsBAgtPH s ozrX1lpucOaWMY6n bNftX2ikwUQ J5M1chps3cMJuXVg

Question 3:

Find the inverse of each of the matrices, if it exists.
35uDrpM4C4xzwJd7xwdQliO53sfaQ1QCgKeOLqBor

Answer
FXzMpekdNgtmEBqNOUV5tg7HpCRAtjlpIYamCZPvqGdyVHc65o33MY93OeRrrnFbtJmMdRrq8jNf4TiMBTOKfNsd JyHWXKYMWJ9npprIgjcX64mZr1Qyc4ZYWznyHSyk4FaDi4

We know that A = IA
1oVx5gJu3flAxMaX5M3za2jSZr8nJvKdmNR2IU c4IRnv rA8t9gkDnrABJcZMhu6ZgTxhi7RYPrC dIzWjP0Mj6WkvcrCDVIL4IoCGxJYF xOPGCwo3A tkfBGHVEuaUMYz3U4

AH

Question 4:

Find the inverse of each of the matrices, if it exists.

Answer
vVgnytvIxk9TfJv2 A1Efa3fuIo8YYPqXXPYSbfFMPfH5BZvtEkLwVT4aWc5NPmZyRFjEr061Gv yaTJmA6NyFzLhKfdRezHFpI5 gwLR CSMUw0Lu7C8moj9ijE4w97nqS W7E

We know that A = IA

zEvtMDW t00SRWKSuknKhlvSgST3 X HoreIEBHq1Tjr6hRKOgJIV8ahgYi5zYJT52Oz9CfnMDuHcf Hr

Question 5:

Find the inverse of each of the matrices, if it exists.

Answer
Ama4FBa 4urm3qzI SECgXfucEYXX6u7bkkYqsCj65DxlwNjyadl6PpnjxYJPKpTpTHx5jCGjTMdDJSeQDV AG0LN8STjeLRXw G3zIJ ZJLFK3a9GNgdDVUYXWGlmsNy2wqaw

We know that A = IA

36K74KW7PtsBA5QceFziY8qlzG2 6XwlIgXnT

Question 6:

Find the inverse of each of the matrices, if it exists.
TBU8IVYDdYtR43PLlhPMJA0Mat1hGGxEqNhLjF7bDlwpVF29k22O4wszjMGXVeGWouBcOo7JjYen6oC1snQdxWqTN8h M1jE74hCMqnLvS3OiyeYYstj5InDYgIfDf9I25NCqBs

Answer
eNks7eKyqGysEX5H1g 0NNJJyEhEdEUPBDsNECBM63 T6c78UhoqQafhMP5 7sqmuNvQjGAc92oiAQbI ia8xsOqz8sLvxDrFXKgyzLZQdmGXxFcublqhvvIWzi7j ct CbEsn0

We know that A = IA

Yct5 npXUXqYpI ZVJRHq7ckAbkw92UPr1iTUj UnGGawp

Question 7:

Find the inverse of each of the matrices, if it exists.
Jk5gmr2rSvMCh VLQJRJIgOmwj3GhnpNaBj8m4OZ1B79ns2O3zEXU xdcrarZQYhmtNGtj02MGvzESAxzzwnPi74qnVJEg aah8t lewQnsb5OXPmKhgaEvp0ygtVYIjMqBgg

Answer

We know that A = AI

yBrOsyYx9p2YPY 0in6p7V0kVJZE0 SlOb23IDjkMGOZD4TWjLxlWzIFagXNV5iNBlLY5lf1rdv IvVXs0UpDK4XS2l0msznK

3dEoC1qFqtdcfm3REY6GoVW5ghUjhZZ7ybNorkysMrmgQ5IRfK9fICeCeBLlNFDjlBRLiMmU5ax e3NuC8AncYanb3W Q9acF7ST7lrSYVjaGusaZZNBbhwnrRtbGCHY3ipt0iM

Question 8:

Find the inverse of each of the matrices, if it exists.wCiol0z2cST

AnsweroLoPQA 8h434ZcuSuT8IOJR2zCG31I1vZar86ZfO9DQRaMYNeaYVS4MmdQOO0WATlkMhAqSv3TGtfXsMQQntQwzsh 2BW8RA8K0UbAT2GowLZUefVgMrf8F1SreuSUFV6TyjmO0

We know that A = IADhA90gzZYw xOnpUPzIv3zJcvLsxUDsnLn8UqOhx3gmbEDkZAkpIaU33EVrDIcXExR1QxEYXIR1 MQnaq8Zuik5ovo2wZHsk1v7qWmlniDwvhcS4IHAdY9zRaFoNrdGHP8bht1E

Question 9:

Find the inverse of each of the matrices, if it exists.
aXBuR1m EmDhlGgbXRiKs rZVMWadUFSRj V6h G7CRfnWnlMRJ7sL8Qa gMD9dQ6h1y8JvirWL1OG 6GAXi UNAPrdjdzTae7Sn0YQnXg 7sXB2dIa6mB1UaGQwsKXoDJRtChI

Answer
riVKvXhL4SaRMvN55ZrsM 8XwrJa4yUF8W xHWNn REgcKkws qeKTThq5Am8UCxxnrte 46Brrr9y3l0t3t8r2rmIhBaNjhTlBcN wS00Z4vWjie2 XqqBpVFZhz0LZUEXE7lI

We know that A = IA
Q 1HM4MoUdjShcuhpBNCxjp1DrycZLaFiCPOjqy4eLfKq1bKpWlURLI7nXyYCFwsR1PbpOK0fUefOJc0S0bZUxuhP9kaVXQDSoF Il9tF6tBz4FqR u5etPWptFtnAm5jpGfDjsRCfjollH IVpnalAWLy88p7eEA04UZIHLRPI6s7LNEupzGPw fFuiin6UWWQywwt0PTS87VeXKlvqCKbbFR7g3qLxTgEIcfuiaRybFhK4EMXgc

Question 10:

Find the inverse of each of the matrices, if it exists.
ui4xVyiavbPuklUAiBe7TXF5Xg3mVwsWMjDOaED1rMvptWRdb180tPexKCv9LCKGh9IbBQBUmiKUe 6sDh 4pinxxAFnvUB7R LFbB9FE34wA4 fzdyM2ebZP4hiyy5jD3fRJM

AnswerfU4Vq2 Vaqx6FEHinYS6b03qDIWZgt9kS2DygvDsBTPJg6JnBmJ5 LuHdW9ko0rDDev UEHMYbkKQsmCdZu U8GPZ494CbEi

We know that A = AIfh XZCSCxOY9i9K5zljxTh9NH6oBk7h6Mq h9RoyvlGNLgZHAGMFwXNTSjhGd7cJ d1 4NheCw4U8S7wuJaeHmcRSVuaThSZ0GemAf7SffDlyaW EdVQI9Q5bSrF7g7n0sbX zQ

xbgucu godzVI4tlsmWGJobQfyg0blke9i9 8GwBr4bd9WCI7eSdkL7dXnS7WHH57D99fWq andCiquoeuw3l ybYQpWm62EolZSiN2shVr Q2hJs 75r7SgGutyRJvdO3B98

Question 11:

Find the inverse of each of the matrices, if it exists.
h7IULl8KSeZ5oAUKUOfXIZJX1yaqyB3bAprdOqMMfg 0YYTYPqlXDYuRQMQ3I6y 8h29 lI

Answer1Mv1WzCmkz1XNjtW33YJyKI2PULOhZ

We know that A = AI
EAJ4tPnLDOiaKBMVeS34TOWy83BmDw4IQL1gXCgfaeeU QTVLlPCob1qhBhuUoTgNizIaSGtuR b9k24oozdkmi0r3pADXK1

SJ 9 4jo70k mApK6fQQqCsuAeuXSNRBf34EbCzV8T3bnER2Isd30zgKPzUsUp2zNhmMJEGRPSAGbqzOwPftg7CVdyslnVJTwvR1C 9mLMXScMnbc0q2lRAEQ WAPy Uf34R 5k

oro1OXcofHys1r0ulxQW0DzR9Q0 x JnoN3oNTV

Question 12:

Find the inverse of each of the matrices, if it exists.
3y2 Kgr3uDuR4rbvlJfMkEgRnIJI5RYXAAVCCQo6DsEpQljj UidwFQeNqw6LD 4NE2B oGrbwl

AnswerpP6ZAq8EFHRJU3yTP EhQojwYX96eCqJCMCi EoWCQ

We know that A = IA
pE9HrHx871u3mZi83aLbnKI5K9id Fg5GKtY0bmW Tfu1OOXXEK3We 9hsJQA oVzkodfnbDFKxKThPYvQb Si3H8LmZn4ORc6BDTlF2x ZjoSKIgc BPIpouJ1VA6vQus2mwTM

Now, in the above equation, we can see all the zeros in the second row of the matrix on the L.H.S.

Therefore, A−1 does not exist.

Question 13:

Find the inverse of each of the matrices, if it exists.

Answer

HXT6WiuLMxKm6dHFFxI3vL7uYH4sAOXH6a Wvw

We know that A = IA
w Z9vUz5mNiCNhliVWIAnU2aTqdWw7ZCSfh4iQp 8POo cFTy7F1v3OHE2EjcxpczMLQCqr19YOskAlsBAb5cBNnJdEfKWjHCNfADuz1Uj6CE Uj5alcbYJsYxEP2we6A1Zn N8

Question 14:

Find the inverse of each of the matrices, if it exists.
H 0FjmOgMQ8PeWlCTb0VW ou30Xe5KiS1EAeRMU5Fst6TIYrQ91V4KQSODF8u8fo2iTsD Q3NFRAjKjPkdDb74Z3stwqKmPoFOFUhs FuFv5EbwlklCfXEuFqzkLrCjAEUpb0WU

Answer9rlOSSXe4UB0JUt WicyFjVY7CIvEKaaccx4U3AkaVuNO fkDXKzIT2w1JiPy09dzMeWLRJcskGIbCpkahx7fscdtpGRftqRQFI6zU2ZUbKarnc k973X1U561UZaFn7 4W6vs0

We know that A = IAmVvCEGbSPr37MBX2vwugj8oI8NIUsJFFZdeXoHmE9r3ilgAEHqC 2 J4T5clzjO0TS5K3jBs9dNYOyIq5mi0ELXdtZe5uhn7Ba5

Applying , we have: 9y0wfBb3Cn Ih3nJ1JWygAk5tS7mEHX8LvI Uf T UqdM4RMYh23RhmYR7fOh74VhvOItoQ1w3YhqAZXBXoCayJ6f6IRLMx P7ufFHp3zXtl2Ue5Wrwrryh6dE5zoRYcS kWq6s2jL4VDzxCLbVq 9gOBNIhTGElJWa7Xi9pI90RCzVukeOov8G0HLaLgBlyv6e2qhbq45tzJxeZ29gjKgcmmGOWwJYbWenjjmopZPZaSVO63KL kjHbEsde5 DmhFHiNIX2byRr1Y

Now, in the above equation, we can see all the zeros in the first row of the matrix on the L.H.S.

Therefore, A−1 does not exist.

Question 16:

Find the inverse of each of the matrices, if it exists.

AnswerXD8mCfK1g 6Y8Nka91 CLTHzht981ZtqXkui8 GeRZTbbV2wU02uvm9ghar0xYObpfceuGDDW1rT99zrlVb2NFEen

We know that A = IA

Applying R2 → R2 + 3R1 and R3 → R3 − 2R1, we have:OrZKbUyOqSUCyZLuTxSc Pr9YQwSBSjBKKyIb6wzdM6U2XDfe5H KyEVselX6X6 EiisHpjIybFmM21ld5xTry L0ca2dHYFSuBG1jqwGDmsi7SCkTBenrs77VwRwBySvwret84

vcsDtJOvM4GYTCncuSZ1s71tngwEuo21vU0LxRSyNkdLYtKe0W A WzMJ6fUS18GaRX17rI8wZo3eap3cBzlEd7Sk9VU497ceYHrmtw70LSlF8DCZFldWm ZrcaQ2KM1Gs7uqDg

XwKXNU1a8fvxL6Bhpfl9nYuk9i7QBYi3KFoD7S96 L89OoykT4ve2Q8O 2lOIRoac0pt8tQVZA zseTKNw s AltMtPrmDwjGePwJfaAGZ1tuWduoLv

Question 17:

Find the inverse of each of the matrices, if it exists.

kZfpsomaQbIno1tf1MKIfzsuXIUMOGeTskKbB2s6E99ygkm1kWoN56qnEZAgHWo2RP2msRGc4GXcY45 du I8Pvim7oSk92SV9ua9MgeUQFuHlqGAA QemqueFo ynss14f7s6Q

Answer
HN E mHP92wa5Xfqv76KaVn9V4Ih5fpVj1tEIf5mZU1ApcVvlg97N aMcZMJPFUFJqsDqR1 ZwshcL9bK1OfokLa8ZryZhWpSnzDtAyxUsCl1i6AHjdMN z4ybihNk1Ijs6tcKc

We know that A = IA
2 pIJQvt6DdPbA13lVtKxuL1Li5qEQjcMSDfQ aRavXndgw9G rLv0lLmmq7 A kvz9QAP04cXeAAeUzq2UBtZBmjNunkEif3yEYe0 gVF2L7ysOLSgipb1lovm3FscgGcVevG0

Applying ,   we have:H7j9rwG6zRA vlA6BaX611j1Xp1z B BuVhFF1nNKpQPMODY5ZyrxPWwg0qHkOzRyhCz3fawxUXG79nilE4lKgf S zu6t1f26sh0TnGkRbC8qJnP9Uc mrpmdDp n041TgGF4

UVjwTaNATQRhvHrjWym8yhhb9FkR0UK5gBF1a4beVnov3rFngjJ0HLdubYB7CuIWKU8 OlxZzuhoeBrROib4CG12kgt zU29bAWjWWZj9 idekRlppx0XQ8v8pL e iuoeK8zDs

S5KJrcSYrnYWtlHHKUPf4jW585gtUmO7xGj i0t0O5Du1jSLpauFBpn0YqCZXZI8 0caYGCIAfxI1XlQAEOY pxGXFLGzVuNbsE0gPl1dVJZOU1tcY6ERtWQuG3l

*Question 18:

Matrices A and B will be inverse of each other only if

(a) AB = BA

(b) AB = 0, BA = I

(c) AB = BA =0

(d) AB = BA =I

Answer

The answer is d

We know that if A is a square matrix of order m, and if there exists another square matrix B of the same order m, such that AB = BA = I, then B is said to be the inverse of

A. In this case, it is clear that A is the inverse of B.

Thus, matrices A and B will be inverses of each other only if AB = BA = I

Miscellaneous Solutions

Question 1:

Let  ,show that , where I is the identity matrix of order 2 and n N cU1LLygzA X1PMpPNE8S4GI0UEnFL81br08ZNXxIfv ej0Jcyuj6djoOQOl1yrb99i5b3NPCWkaj3IDR FqAmlgMSVtzqJ7M i7FuupqROwao6Utz2SxlVU8cI

Answer

It is given that
svTNKa 1T67IXzkPRZOQ087B3UsIBRTC4mznWnbuqnTr1ZPGvFd6p2KHrxdiDWeXeV4NR1fmS8Hwwh4C7saBLtS2d70mvOlaimotfRUioW

We shall prove the result by using the principle of mathematical induction. For n = 1, we have:

972bHm5HguiYcXJLVwvK7dID9PECJiSxESO1pxRoBUz4GD UD3WNuHp0ZpvrEMoq pYQdAwd0YrfE27598r4Fbpnd1KZtSu8nodKdCez3ZLN6A9w1DXG2SLcYR7w3pQLF1lOqY

Therefore, the result is true for n = 1. Let the result be true for n = k.

That is,
FSN5FLdmofUTnuUPVTp XZSIkeNLxKjTQmosQ7y1 bOx mbuaZWjtvVju01aS3lDkhAJtreqUtNUDBxAYVoBQQ07DI Ki7kEiJ4ZYCz4fOVv1iePiWBgUZjXEpP7aby YrRSr A

Now, we prove that the result is true for n = k + 1. 

Consider

HO aXm4Cl4Kir2swEP69Hlr2Bnhp AG5KkTIMTh d2MUJShIqi o0kDd dJaAYas1mtGKB xb3gHFNIQk32Ttfk R4iCcb4e5evJUta6lAPl47wrh8L3Us0VTiKpEimw4XjikGQ

From (1), we have:

kUfU0h74wG 2Ba3dlZh2iAa ctN8tPeY9 gGSSv6bI6aEU rQa GkR9urstoq nIEWeQJpnvGLidpxEKQM4 Fgdaf55u4el6Z5oJ

Therefore, the result is true for n = k + 1.

Thus, by the principle of mathematical induction, we have:
5Rr AQHdnNx1k1NN80XBkBzviKiYAHh NmyMqo1odzWbQDM7zFzvC8awb3KRPjdHQ HnrZ5FPd26Q5hHk2G16MxiedgbqagmH1hMeqKqSsVhYuxMft0YnlwEJSTS4Dwx 7

Question 2:BfBR 4YIRvjtMxG3TOElnvvo4kr20ghlggVC0DnP65hInfXxrB1hurZxIVhzUhjvXhdoCLO4mkLe0sB1Cy0BvguZ 7s9XE8hQ 7oDwJM2Pd7CVZhLtDWNnBz3nX6kT6YNKCzjIk
mJNEzmvIn6rp9kjXasmWnJ2cdT zL999MLKQJTqJbpOQvySF9eTa8rx5q5xkGMV 5DDnulJVNgAQqlfnfXNXgx5FuriXtZLCFAJbBkBE08Vl9193i7Yk6AqqQp3PA V4tQds J0

If prove that, 

AnswermJNEzmvIn6rp9kjXasmWnJ2cdT zL999MLKQJTqJbpOQvySF9eTa8rx5q5xkGMV 5DDnulJVNgAQqlfnfXNXgx5FuriXtZLCFAJbBkBE08Vl9193i7Yk6AqqQp3PA V4tQds J0

It is given that

We shall prove the result by using the principle of mathematical induction. For n = 1, we have:

D2swGU xOqdDFNsWIUZPG82bXwmVA4rEyog6

Therefore, the result is true for n = 1. Let the result be true for n = k.

AiF8bEyBdc2vmSdwDLK3mqEpDirZv3G0CZ truD2KQ88Gdw9udkkYNvz2aWt5zcwZ1E10sFiQp7pVzkuQWwcNn53Si xV0GDYj

That isC8eM384Mo16I2i4ht

Now, we prove that the result is true for n = k + 1.

Therefore, the result is true for n = k + 1.

Thus by the principle of mathematical induction, we have:
BfBR 4YIRvjtMxG3TOElnvvo4kr20ghlggVC0DnP65hInfXxrB1hurZxIVhzUhjvXhdoCLO4mkLe0sB1Cy0BvguZ 7s9XE8hQ 7oDwJM2Pd7CVZhLtDWNnBz3nX6kT6YNKCzjIk

*Question 3:

If , then prove  where n is any positive integer 

Answer

It is given that
f7d tQdkoNvL7vDnRnqygc2yUo0sAEXt6aMIGIuOGHtt FMFr9xfA5qwOzYPwyR4H6LIjjaSwTFpvI QrLd7d1qjj14Xy8jbvtUXWLkJP

We shall prove the result by using the principle of mathematical induction. For n = 1, we have:

FXw7KrpMSECHrC3AbP3RBQHI9sr iQgmzAemHxwN ll8Dok80R3DRg lBMtz2maxx7ZJMVHGsGrazWLAFzNtGGD4dBTFmuk7fu2tU4QvAlGXY6SYDYh9WmS wXq 0g51rED27Uw

Therefore, the result is true for n = 1. Let the result be true for n = k.

That is,
wMidXL0xUUMQrfic0byv8fToDiXYy7hIg9sxlPKVH7srmQGpX7hkV64DU4YqLRCvO7oEQ3TZlbHqL6T

Now, we prove that the result is true for n = k + 1.

Therefore, the result is true for n = k + 1.aHiovNs uQYg5i 0XJVccZtABjamMHXyG fdWyjiDyGQwnf7FqEs9Pdy 6ZHtBUb2ufk65PwIjpi5eAjw4TVebOpIj zDR8Kql2F 1fwp6KJP3GbE8PlbFhGFRQXmTCkZAXl6WU

Thus, by the principle of mathematical induction, we have:
cu13bWoloW9EbY n0HshqTBKgJAxVcVahThrBiHAUhvv8MQ5alTdyh gP t1nPsJgcRrUK00 qDJSA iencj9rd54HuMG1dBJ7gdpu1l0Ip0WhdryPvq4BQgVby5NwpY0U

Question 4:

If A and B are symmetric matrices, prove that AB BA is a skew symmetric matrix. 

Answer

It is given that A and B are symmetric matrices. Therefore, we have:

VP1vU698 kBUPb EFr6xFjOEqqBjm33j7kMGuFjNWqNKIMxmZPeoiIMTXms4R9hVI8LLnyOTaAhbBzL5bloKQFzbPLitwlPY6ftar7jKllk 7DR7AdhWbdDqL46 urlSPWgJeS8

Thus, (AB BA) is a skew-symmetric matrix.

Question 5:

Show that the matrix lYZ6Dr5meqbRHZCWUYL1EreAtQX02ntwoHAiA2HuENJevJTF9msga KzpM tJea9aIubsi96TTVEnlHVs0 FTOAc6QuLR3ZHX8hqIjFNp58 MDrgjF1BpsgVRtUaEFoHEtBTdVkis symmetric or skew symmetric according as A is symmetric or skew symmetric.

Answer

We suppose that A is a symmetric matrix, then … (1) Consider

Thus, if A is a symmetric matrix, thenis a symmetric matrix. Now, we suppose that A is a skew-symmetric matrix.7tJHrLx boxVIh hoEn751l MQU3hKM5Jh9hHy8mZj2bcrpsZ4uOu8t9O7 MP4ZDGVSboa8CRDCjDM47TU3f38FsT9ZTfUe2pTS 9ysPVOFYTYlladI8Ajk7MBT0byXMXQMNlwM

Then, dDIzAsohYCy6uR YU5WgEL895Su6bA8mnW1dFm4Ol3invi4vBbr7Zn9uVXcKOPN49jnZbpEZ9y4Cg5X9M2cpWjGVWvjO91KpKXreeFBige y9JvRkeEIz5FSb24rQtnK B2F3Wk

dTkPJ 4zgmZPoyS LbexhxGG2y2MYV

Thus, if A is a skew-symmetric matrix, then lYZ6Dr5meqbRHZCWUYL1EreAtQX02ntwoHAiA2HuENJevJTF9msga KzpM tJea9aIubsi96TTVEnlHVs0 FTOAc6QuLR3ZHX8hqIjFNp58 MDrgjF1BpsgVRtUaEFoHEtBTdVkis a skew-symmetric matrix.

Hence, if A is a symmetric or skew-symmetric matrix, then lYZ6Dr5meqbRHZCWUYL1EreAtQX02ntwoHAiA2HuENJevJTF9msga KzpM tJea9aIubsi96TTVEnlHVs0 FTOAc6QuLR3ZHX8hqIjFNp58 MDrgjF1BpsgVRtUaEFoHEtBTdVk is a symmetric or skew- symmetric matrix accordingly.

*Question 6:

Solve system of linear equations, using matrix method.
R5ZkZJjhCi3ewoKFCdnkEya6p0eOcc2jkXwTQ5cRt2ykcDKmGR33PyDzEx8P2lc5HnOZRnFJEgdJAZEBdla9tls6U4K0jzRjC BbYi4S1qsW XRW9JMszhf82 zmzv9gOmheCYULlMS

Answer

The given system of equations can be written in the form of AX = B, whereodjBB5vRKmG3V azv4dENGlEd3V6BVrc8xFZe2s7ULGdbvevTSuy2sQD RwS

Thus, A is non-singular. Therefore, its inverse exists.

CRf5yZ8Wwy6hlQn9IQh8kDj2N8bPWgqZAmhHttEzreFrKJBOtMfigULjYmoAhm5tGl0ZjBWqJuU6tikUS x4cOuYTG1ZZrWQ99lH1W3uZ5XSTXln7ql4DX2

djv9wg5QAvH9EyPsYzESpl2N7IxCjwJIgvAFX5wwobvHcLIthi0vie578hFyl6Ccmw6Fk80nuYJQlxhgUcE0aS3dW TBxGiD239Ug9CwqxydyeiZ9viWSiAv1YpgTUeiNjjil s

Question 7:

For what values of

Answer 

We have:

∴4 + 4x = 0

x = −1

Thus, the required value of x is −1.

Question 8:

If , show that8 tBkZTvACd1HfNFzDDKSafygeqzrG6 JMKgFuLyMEjRSiQXUiJ5yn kHh vcroGTbhOdnr

Answer
dVT89 JACrDpYQr02 rbNAh8T V8s9FcgcZAOl5CIoIrTGrX RxVB9 y oRmbMDC2296fTmkBIFPmHHifjUiFZDpi4uc ckpJeZQ2G7sbPdaXMF8xuyaV20c4idPcKzA19Qd4 o

*Question 9:

Find x, ifWrKGLosbvWgeGF1FFF7aYHF RJQSsDi30vtkuVBCbGr6emCudmZ7M1wyInDGQn1bJi3KUFE1vogWouXjcnBfyd x0fbCrYyxPlOkhmkfUVS

Answer 

LlhNCU6rE JTQ6w54Cc8gHO9kctv5f

*Question 10:

A manufacturer produces three products x, y, z which he sells in two markets. Annual sales are indicated below:

 

Market     Products

I                  10000    2000   18000

II                 6000     20000   8000

 

If unit sale prices of x, y and z are Rs 2.50, Rs 1.50 and Rs 1.00, respectively, find the total revenue in each market with the help of matrix algebra.

If the unit costs of the above three commodities are Rs 2.00, Rs 1.00 and 50 paise respectively. Find the gross profit.

Answer

The unit sale prices of x, y, and z are respectively given as Rs 2.50, Rs 1.50, and Rs 1.00.

Consequently, the total revenue in market I can be represented in the form of a matrix as:

The total revenue in market II can be represented in the form of a matrix as:

Therefore, the total revenue in market I is Rs 46000 and the same in market II is Rs 53000.

The unit cost prices of x, y, and z are respectively given as Rs 2.00, Rs 1.00, and50 paise.

Consequently, the total cost prices of all the products in market I can be represented in the form of a matrix as:

Since the total revenue in market I is Rs 46000, the gross profit in this market is (Rs 46000 − Rs 31000) Rs 15000.

The total cost prices of all the products in market II can be represented in the form of a matrix as:

Since the total revenue in market II is Rs 53000, the gross profit in this market is (Rs 53000 − Rs 36000) Rs 17000.

Question 11:

Find the matrix X so that

Answer

It is given that:

The matrix given on the R.H.S. of the equation is a 2 × 3 matrix and the one given on the L.H.S. of the equation is a 2 × 3 matrix. Therefore, X has to be a 2 × 2 matrix.

Now, let

Therefore, we have 

Equating the corresponding elements of the two matrices, we have:

Thus, a = 1, b = 2, c = −2, d = 0

Hence, the required matrix X is

Question 12:

If A and B are square matrices of the same order such that AB = BA, then prove by

induction that . Further, prove that  for all n ∈N

Answer

A and B are square matrices of the same order such that AB = BA.

For n = 1, we have:

Therefore, the result is true for n = 1. Let the result be true for n = k.

Now, we prove that the result is true for n = k + 1.

Therefore, the result is true for n = k + 1.

Thus, by the principle of mathematical induction, we have Now, we prove that  for all n ∈N

For n = 1, we have:

Therefore, the result is true for n = 1. Let the result be true for n = k.

Now, we prove that the result is true for n = k + 1.

Therefore, the result is true for n = k + 1.

Thus, by the principle of mathematical induction, we have , for all natural numbers.

Question 13:

Choose the correct answer in the following questions:

If  is such that       then

  1.  

B.

C.

D.

Answer

Answer: C

On comparing the corresponding elements, we have:

Question 14:

If the matrix A is both symmetric and skew symmetric, then

  1. A is a diagonal matrix
  2. A is a zero matrix
  3. A is a square matrix
  4. None of these 

Answer 

Answer:B

If A is both symmetric and skew-symmetric matrix, then we should have

Therefore, A is a zero matrix.

Question 15:

If A is square matrix such that then is equal to

  1. I A
  2. 3

Answer

Answer: C

NCERT Solutions Math Class 12 Chapter 3 – Matrices

Students must manage a variety of tasks throughout their academic careers, making it necessary to seek expert assistance in order to get decent scores. Maths is a topic that can be applied if the fundamental principles are understood. Matrices is a crucial chapter in the NCERT Solutions for Class 12 Maths. It’s also a useful and important instrument in the field of mathematics. When compared to other direct ways, this Mathematical tool greatly simplifies our job. The development of the notion of matrices stems from a desire to find quick and easy solutions to solve a system of linear equations. Matrices aren’t just for displaying the coefficients of a system of linear equations.

 

Topics to study in Chapter 3 Class 12 Math

 

Section no

Topics

3.1

Introduction

3.2

Matrix

3.3

Types of Matrices

3.4

Operations on Matrices

3.5

Transpose of a Matrix

3.6

Symmetric and Skew Symmetric Matrices

3.7

Elementary Operation (Transformation) of a Matrix

3.8

Invertible Matrices

 

Weightage of Class 12 Math chapter 3 – Matrices

 

Chapter 

Marks

Matrices

10 Marks

 

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One of the top IIT JEE coaching institutes is Swastik Classes. Shobhit Bhaiya and Alok Bhaiya, pioneering mentors of IIT JEE Coaching Classes, started Swastik Classes in Anand Vihar. Over the last 15 years, they have educated and sent over 2000+ students to IITs and 5000+ students to different famous universities such as BITS, NITs, DTU, and NSIT. When it comes to coaching programmes for IIT JEE, Swastik Classes is the top IIT JEE Coaching in Delhi, favoured by students from all over India.

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The study process in Swastik courses is separated between pre-class and post-class work, which is one of the most significant aspects. They are precisely created to improve the student’s mental ability and comprehension.

Conclusion                                                                                  NCERT Solutions for Class 12 Maths Chapter 3 “Matrices” provide students with a comprehensive understanding of the concept of matrices and their operations. The chapter covers a variety of topics such as types of matrices, matrix operations such as addition, subtraction, multiplication, and inverse of matrices, and properties of matrix operations.
The solutions offered by Swastik Classes provide detailed explanations and numerous solved examples to help students understand the concepts more effectively. The step-by-step guidance provided in the solutions also assists students in developing problem-solving skills and building a strong foundation in matrix algebra.

Why choose SWC as IIT JEE Coaching in Delhi

Videos on Class 12 Math Matrices

 

What are the main topics discussed in NCERT Solutions for Class 12 Maths Chapter 3?

In Mathematics, matrices are one of the easiest chapters which when understood would be fun to solve. Matrix, types of matrices, operations on matrices, transpose of a matrix, symmetric and skew symmetric matrices, elementary operation on matrix and invertible matrices are the main topics discussed in this chapter. These topics are explained in a simple language to help students score well in the board exams irrespective of their intelligence quotient.

 

Why should we learn about matrices in NCERT Solutions for Class 12 Maths Chapter 3?

Matrices are rectangular arrays of numbers which are represented in rows and columns. Various mathematical operations like multiplication, addition, subtraction and division can be performed using matrices. Representing the data related to infant mortality rate, population etc. are the widely used areas where matrices are used to simplify the calculation of complex data. The other substantial use of matrices are statistics, plotting graphs and various scientific research purposes. The method of solving difficult linear equations are also made simple using the matrices.

 

Does NCERT Solutions for Class 12 Maths Chapter 3 help you to score well in the board exams?

Students should first solve the easier problems and then move on to the problems of higher level difficulty. After completing each exercise, students will be able to analysis the areas in which they are lagging behind. By practising the weaker concepts numerous times, students will be able to perform well in the board exams. Short cut tips are also highlighted to help students understand the easier way of solving complex problems effortlessly.

 

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2021 Result Highlight of Swastik Classes

NCERT Solutions Class 12 Maths Chapters

  • Chapter 1 Relations and Function
  • Chapter 2 Inverse Trigonomtry
  • Chapter 3 Matrices
  • Chapter 4 Determinants
  • Chapter 5 Continuity and Differentiability
  • Chapter 6 Applications of Derivatives
  • Chapter 7 Integrals
  • Chapter 8 Application of Integrals
  • Chapter 9 Differential Equations
  • Chapter 10 Vector
  • Chapter 11 Three Dimensional Geometry
  • Chapter 12 Linear Programming
  • Chapter 13 Probability

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