Determinants Matrices Question 168
Question: If A is a square matrix such that $ A^{2}=A $ , then $ {{(I+A)}^{3}}-7A $ is
Options:
A) 3I
B) 0
C) I
D) 2I
Show Answer
Answer:
Correct Answer: C
Solution:
- [c] Given $ A^{2}=A. $ Now, $ {{(I+A)}^{3}}-7A=I^{3}+3I^{3}A+3IA^{2}+A^{3}-7A $
$ =I+3A+3A+A-7A $
$ =I+O=I $
BETA
