JEE Main 2026 Mathematics question
Consider the matrices and . If matrices P and Q are such that PA = B and AQ = B, then the absolute value of the sum of the diagonal elements of 2(P + Q) is .
Answer: 34
Solution
P = BA⁻¹ and Q = A⁻¹B. Computing, tr(P) + tr(Q) = −17, so |2(tr P + tr Q)| = 34.