Let and . If denotes the sum of all diagonal elements of the matrix , then has value equal to:
- (A)1
- (B)2✓ Correct
- (C)3
- (D)0
Answer: (B)
Solution
The trace is linear, so taking traces of both given equations turns them into two scalar equations:
Solving the pair gives and , so
Solving the pair gives and , so
JEE Main · 2021 · 18 Mar 2021 · Shift 1 · Single correct option