Question

find all the real zeros of the polynomial function. determine the multiplicity of each zero.
f(x)=2x^4-2x^2-40

Answer 1

this is an equation reducible to a quadratic

let u = x^2

or just factorise

\[(x^2 - 5)(2x^2 + 8) = 0\]

then \[x^2 = 5... and .... x^2 = -8\]

I'll leave you to identify the roots from here... 2 are irrational and 2 are complex