For all complex numbers z, let

f(z) = z^2 if z is not real

f(z) = -z^2 if z is real.

Find f(f(f(f(-i)))).

Guest Dec 17, 2020

#1**0 **

-i is not real. Thus, we square it. -i^2 = i^2 =-1. -1 is real. Thus, we square 1. After a whole chain of squaring 1 and -1, we end up eventually with 1, so the answer is 1.

Pangolin14 Dec 18, 2020