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Let P and Q be `3xx3` matrices with `P!=Q` . If `P^3=""Q^3a nd""P^2Q""=""Q^2P`, then determinant of `(P^2+""Q^2)` is equal to (1) 2(2) 1 (3)0 (4) 1 |
Answer» `P^3 = Q^3 `eqn(1) `P^2Q = Q^2P`eqn(2) `(1)- (2)`equation `P^3 - P^2Q - Q^3 - Q^2P` `P^2(P-Q) = Q^2(Q-P)` `P^2(P-Q) = -Q^2(P-Q)` `(P^2 + Q^2)(P-Q) = 0` `P-Q= 0 or P^2 + Q^2 = 0` `P-Q= 0 ` NOT POSSIBLEso`P^2 + Q^2 = 0` Option 3 is correct |
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