COMEDK2013MathematicsBinomial Theorem
The smallest positive integer n for which (1+i)^ 2 n =(1-i)^ 2 n is
Options
- A1
- B2
- C3
- D4
Correct answer
B. 2
Step-by-step solution
We have, aligned & &(1+i)^ 2 n =(1-i)^ 2 n & & ( 1+i 1-i )^ 2 n =1 & & ( 1+i 1-i 1+i 1+i )^ 2 n =1 & & ( 1+i²+2 i 1-i² )^ 2 n &=1 & & ( 1-1+2 i 1+1 )^ 2 n &=1 & & i^ 2 n &=1 & & 2 n &=4 & n &=2 aligned