What is the inverse of the matrix ?

Answer and explanation

Correct answer: C.

  1. Step 1: Compute determinant: .
  2. Step 2: For a matrix , .
  3. Step 3: .
Answer
.
Why not the others: The second option forgets to negate the off-diagonal entries; the third omits division by ; and the fourth adds .

Practise more Vectors, 3D Geometry and Probability.

Free questions with an explanation for every one, and full timed CBSE Class 12 mock tests.