SOLUTION: Find a polynomial f(x) of degree 3 that has the indicated zeros and satisfies the given condition.
-2i, 2i, 5; f(1) = 80
I tried this:
(x+2i)(x-2i)(x-5) = x^3-5x^2+4x-20
Question 731799: Find a polynomial f(x) of degree 3 that has the indicated zeros and satisfies the given condition.
-2i, 2i, 5; f(1) = 80
I tried this:
(x+2i)(x-2i)(x-5) = x^3-5x^2+4x-20
Then I solved this:
80=a(1+2i)(1-2i)(1-5)
80=a(20)
a=4
Then I combined the two, and I got:
4(x^3-5x^2+16x-80)
=4x^3-20x^2+16x-80
This is wrong. Any ideas where I went wrong? Answer by vabryant09(1) (Show Source):
(