﻿ Class 12 NCERT Math Solution
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TOPICS
Exercise - 3.3

Question-1 :-  Find the transpose of each of the following matrices: Solution :-
```(i) ```
```(ii) ```
```(iii) ```

Question-2 :- (i) (A + B)′ = A′ + B′,
(ii) (A – B)′ = A′ – B′

Solution :-
```(i) ```
```(ii) ```

Question-3 :- (i) (A + B)′ = A′ + B′,
(ii) (A – B)′ = A′ – B′

Solution :-
```(i) ```
```(ii) ```

Question-4 :- Solution :-
``` ```

Question-5 :-  For the matrices A and B, verify that (AB)′ = B′A′, where Solution :-
```(i) ```
```(ii) ```

Question-6 :- Solution :-
```(i) ```
```(ii) ```

Question-7 :- Solution :-
```(i) ```
```(ii) ```

Question-8 :- (i) (A + A′) is a symmetric matrix
(ii) (A – A′) is a skew symmetric matrix

Solution :-
```(i) ```
```(ii) ```

Question-9 :- Solution :-
``` ```

Question-10 :-  Express the following matrices as the sum of a symmetric and a skew symmetric matrix: Solution :-
```(i) ```
```(ii) ```
```(iii) ```
```(iv) ```

Question-11 :-  If A, B are symmetric matrices of same order, then AB – BA is a
(A) Skew symmetric matrix   (B) Symmetric matrix   (C) Zero matrix   (D) Identity matrix

Solution :-
```  A and B are symmetric matrices, therefore, we have:
A' = A, B' = B .........(I)
Consider
(AB - BA)' = (AB)' - (BA)' [(A - B)' = A' - B']
= B'A' - A'B'   [(AB)' = B'A']
= AB - BA       [By equation I]
Thus, (AB − BA) is a skew-symmetric matrix.
```

Question-12 :- (A) π/6   (B) π/3   (C) π   (D) 3π/2

Solution :-
``` 