JEE Main2003MathematicsComplex NumberActual
If ( 1+i 1-i )^x=1 then
Options
- Ax=2 n+1 , where n is any positive integer
- Bx=4 n , where n is any positive integer
- Cx=2 n , where n is any positive integer
- Dx=4 n+1 , where n is any positive integer
Correct answer
B. x=4 n , where n is any positive integer
Step-by-step solution
( 1+ i 1- i )^ x =1 [ (1+ i ) 1- i ^2 ]^ x =1 ( 1+ i ^2+2 i 1+1 )^ x =1 ( i )^ x =1 ; x =4 n ; n 1⁺