math
posted by aria on .
use the given zero to find the remaining zeros of the function:
F9x)=x^35x^2+4x20; zero:2i
I don't get it. Can someone please show me what to do with this?

if 2i is a zero, so is 2i
so, (x2i)(x+2i) = x^2+4 divides f(x)
doing the division, we have
f(x) = (x5)(x^2+4)
so, the zeros are 5,2i,2i