Question

use the given zero to find the remaining zeros of the function

P(x)= x^5 - x^4 - 4x^3 + 8x^2 - 32x + 48 ; zero -2i

Answer 1

If you have a complex root, then you know there must be another root that is the complex conjugate of that root.

So you have two roots: -2i, 2i.

Now you can rewrite P(x) = (x+2i)(x-2i)*[a*x^3+b*x^2+c*x+d] where a, b, c, d are determined by equating with the P(x) form first given.

Then you just need to find three roots out of the third degree polynomial you've defined there.

Answer 2

thanks :)