Find all zeros of f(x)=x^4+5x^2-36 by completley factoring the polynomial.

Question

f(x)=x^4+5x^2-36=(x^2-4) (x^2 +9) = ?

List four zeros of the function:

Real zeros:

complex zeros:

Answer 1

2,-2

3i, -3i

factors are

(x+2)(x-2)(x+3i)(x-3i)

set each factor =0 and solve for x