Question

Factor the polynomial completely. (If it is not factorable using integers, enter NF.)
x^4 -13 x^2+36

Answer 1

\[(x-3) (x-2) (x+2) (x+3)
\]

Answer 2

\[x^{4}-13x^{2}+36=\left( x^{2}-9 \right)\left( x^{2}-4 \right)=\left( x+3 \right)\left( x-3 \right)\left( x+2 \right)\left( x-2 \right)\]