Question

How do i factor: x^4-5x^2+4

Answer 1

what?

Answer 2

(x-2)(x-1)(x+1)(x+2)

Answer 3

The above equation can be written as
\[x^4-4x^2-x^2+4\]
\[x^2(x^2-4)-1(x^2-4)\]
\[(x^2-4)(x^2-1)\]
\[(x-2)(x+2)(x-1)(x+1)\]