If (1+i1−i)x=1, then
(1+i1−i)x=1⇒[(1+i)21−i2]x=1, ⇒[(1+i2+2i1+1]x=1⇒ ix=1 ∵ x=4n,nEI+.
If A=[3−41−1], then prove that An=[1+2n−4nn1−2n], where n is any positive integer.