BITSAT2021MathematicsComplex NumberActual
If z is a complex number such that z²=( z )² , then
Options
- Az is purely real
- Bz is purely imaginary
- Ceither z is purely real or purely imaginary
- DNone of these
Correct answer
C. either z is purely real or purely imaginary
Step-by-step solution
Let z=x+i y , then its conjugate z =x-i y Given that z²=( z )² array l x²-y²+2 i x y=x²-y²-2 i x y 4 i x y=0 array