PreCal.
posted by phyllys on .
find all the zeros of the following polynomial. Write the polynomial in fraction form. Show all the work.
f(x)= x^4+3x^240

Let x^2 = y
y^2 +3y 40 = 0
(y+8)(y5) = 0
y = 8 or 5
x = sqrty = +/ isqrt8 or +/ sqrt5
f(x) = (x  sqrt5)(x + sqrt5)(x^2 +8)