NCERT Class 12-Mathematics: Exemplar Chapter – 3 Matrices Part 14 (For CBSE, ICSE, IAS, NET, NRA 2022)

Doorsteptutor material for IMO-Level-2 Class-3 is prepared by world's top subject experts: fully solved questions with step-by-step explanation- practice your way to success, Get full length tests using official NTA interface: all topics with exact weightage, real exam experience, detailed analytics, comparison and rankings, & questions with full solutions.

Question 37:

Find inverse, by elementary row operations (if possible) , of the following matrices

(i)

(ii)

Answer:

(i) Let

In order to use elementary row operations we may write .

where B is the inverse of A

(ii) Let

In order to use elementary row operations, we write

Since, we obtain all zeroes in a row of the matrix A on LHS, so dose not exist.

Question 38:

If , then find values of .

Answer:

As the matrices are equal. So corresponding elements of both the matrix must also hold the equality.

Hence, we get:

When

And when

Thus,

; or ; and … ans

Question 39:

If , Find a matrix C such that is a null matrix.

Answer:

We have,

Let

Also,

And