Question

Complete the steps to find all zeroes of the function f(x) = x4 − 4x3 − 4x2 + 36x − 45. This function has roots.

Answer 1

Steps?

A graph shows zeros to be ±3. Factoring those out leaves the quadratic
  (x-2)² +1
which has complex roots 2±i.

The function has roots -3, 3, 2-i, 2+i.

Answer 2

this function has 4 roots.