Question

if z-1/z=4 then z^2+1/z^2=

Answer 1

z-1/z =4

Square on both,

(z-1/z)² =4²

z² +1/z² -2(z×1/z) =16

z²+1/z² -2 =16

z²+1/z² =16+2

z²+1/z² =18




I hope this will help you


-by ABHAY