find all the zeros of the following polynomial. Write the polynomial in fraction form. Show all the work.

Question

f(x)= x^4+3x^2-40

Answer 1

Let x^2 = y
y^2 +3y -40 = 0
(y+8)(y-5) = 0
y = -8 or 5
x = sqrty = +/- isqrt8 or +/- sqrt5
f(x) = (x - sqrt5)(x + sqrt5)(x^2 +8)