# NCERT Class 12-Mathematics: Exemplar Chapter –3 Matrices Part 5

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## 3.3 EXERCISE

### Short Answer (S.A)

**Question 1:**

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

**Answer:**

. If matrix has elements then its order will be either or .

**Question 2:**

In the matrix , write

(i) The order of the matrix A

(ii) The number of elements

(iii) Write elements

**Answer:**

(i)

(ii)

(iii)

**Question 3:**

Construct matrix where

(i)

(ii)

**Answer:**

(i)

(ii)

**Question 4:**

Construct a matrix whose elements are given by

**Answer:**

**Question 5:**

Find values of and if , where

**Answer:**

Also,

By equality of matrices we know that each element of A is equal to the corresponding element of that is for all and .

And

**Question 6:**

If possible, find the sum of the matrices A and B, where

**Answer:**

Here, A and B are of different orders. Also, we know that addition of two matrices A and B is possible only if order of both the matrices A and B should be same.

Hence, the sum of matrices A and B is not possible.

**Question 7:**

If

(i)

(ii)

(iii) A matrix Z such that is a zero matrix.

**Answer:**

(i)

(ii)

And

(iii)

Also,

We see that Z is the additive inverse of or negative of