Question
Question: If A<sup>2</sup> = A, then (I + A)<sup>4</sup> is equal to –...
If A2 = A, then (I + A)4 is equal to –
A
I + A
B
I + 4A
C
I + 15 A
D
None of these
Answer
I + 15 A
Explanation
Solution
(I +A)2 (I + A)2 = (I + IA + A I + A2)2
(I + 2A + A)2 = ( I + 3A)2
= I + 9A2 + 3IA + 3AI
= I + 15 A