if A^2=A...then (I+A)^4=?
A2=A(GIVEN)
(1+A)4=((1+A)2)2
=(12+A2+2*1*A)2
=(1+A+2A)2......SINCE A2=A
=(3A+1)2=9A2+1+6A
=9A+1+6A=15A+1
(1+A)4=((1+A)2)2
=(12+A2+2*1*A)2
=(1+A+2A)2......SINCE A2=A
=(3A+1)2=9A2+1+6A
=9A+1+6A=15A+1