AP EAMCET2014MathematicsComplex Number
The least positive integer n for which (1+i)^n=(1-i)^n , is
Options
- A8
- B2
- C4
- D6
Correct answer
C. 4
Step-by-step solution
Given, (1+i)^n=(1-i)^n aligned & (1+i)^n (1-i)^n =1 & [ (1+i) (1+i) (1-i) (1+i) ]^n=1 & [ 1^2+i^2+2 i 1^2-i^2 ]^n=1 & [ 1-1+2 i 1+1 ]^n=1 & ( 2 i 2 )^n=1 & (i)^n=1 & n=4 & aligned