Q48 / 90 · JEE Main 2021 (27 Jul Shift 2) · Mathematics

Let A and B be two 3×3 real matrices such that A2-B2 is invertible matrix. If A5=B5 and A3 B2=A2 B3, then the value of the determinant of the matrix A3+B3 is equal to :

  • A
    2
  • B
    4
  • C
    1
  • Correct answer
    D
    0

Solution

Let C=A2-B2;C≠0

and A5=B5   ...1

A3 B2=A2 B3   ...2

Subtracting equation 2 from 1, we get A5-A3B2=B5-A2B3

⇒A3 A2-B2+B3 A2-B2=O

Post multiplying inverse of A2-B2:

A3+B3=O⇒A3+B3=0

Hence, the correct answer is option: 'D'.

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