How can you factor u4-13u2 plus 36?

Answer 1

I don't factor these. I am lazy, so I use the quadratic formula.

-b +/- sqrt(b^2-4ac)/2a

a = 2

b = 13

c = 6

u = - 13 +/- sqrt[13^2 - 4(2)(6)]/2(2)

u = - 13 +/- sqrt(121)/4

u = [- 13 +/- 11]/4

u = - 1/2

u = - 6

My TI-84 confirms this answer. You check in original equation.

Answer 2

(u + 3)(u + 2)(u - 3)(u - 2)