If (1+i1−i)m = 1 then the least integral value of m is
2
4
8
None of these
1+i1−i=1+i1−i×1+i1+i=(1+i)22=2i2 = i
∴ (1+i1−i)m = im = 1 (as given)
So the least value of m = 4 ( ∵ i4 = 1 )