Question

8. z^2+zbar^2 is:
(A) Real
(C) Imaginary
(B) complex
(D) rational​

Answer 1

Answer:

let z = x+ iy so z^2 = x^2 - y^2 + 2ixy

so z bar = x - iy so @ bar ^2 =x^2 - y^2 -2ixy

z^2 +zbar^2 = 2( x^2 - y^2) real

so option a is correct ☺