Question

State how many imaginary and real zeros the function has.

f(x) = x3 + 5x2 - 28x - 32

Answer 1

Use factor theorem to find the factor of f(x).
By trial and error, we got f(-1) = 0
So, x+1 is one of the factors.
Find the other factor(s) by division.
Then, set f(x) = 0
x3 + 5x2 - 28x - 32 = 0
(x+1)(other factor(s)) = 0
x+1=0 or other factor(s) = 0.
It shouldn't be difficult.