Question

Find all the zeroes of the polynomial function f ( x ) = x 3 − 5 x 2 + 6 x − 30

Answer 1

5, ±√6i

Explanation:

f(x)=x^3-5x^2+6x-30=x^2(x-5)+6(x-5)=(x^2+6)(x-5)

to make f(x)=0, x^2+6=0 or x-5=0

x^2=-6; x=±√6i

x-5=0; x=5