Question

Find the least positive integral value of n for which (1 i/1-i)^n is real

Answer 1

Answer:

2

Step-by-step explanation:

(1+i/1-i)^n

{( 1+i/1-i)× [1+ i/1+i]}^n

[(1+i)(1+i)/1-(-1)]^n

{1/2 [1+2i-1]}^n

[2i/2]^n

i^n

if n=2 then i^2= -1(real)

hence n =2