Question

Please help! Algebra 2

Find all zeros of the polynomial function

3. f(X)= X^4- 5X^2-36

Answer 1

well it's an equation that is reducible to a quadratric...

so think about \[x^4 = (x^2)^2\]

so you get

\[f(x) = (x^2)^2 -5(x^2) - 36\]

this can be factorised to

\[f(x) = (x^2 - 9)(x^2 + 4)\]

now you can find the solutions