If A is a square matrix such that $A^2 = A$ and I is the identity matrix of the same order as A, then $(I+A)^2-3A$ is equal to
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → $I$
Given$A^2 = A$, $I$ is the identity matrix
Compute $(I + A)^2 - 3A$:
$(I + A)^2 - 3A = I^2 + IA + AI + A^2 - 3A = I + A + A + A - 3A = I + 3A - 3A = I$