Question

Factor the polynomial x^4+10x^2+16

Answer 1

You can let t = x^2, Now you get:
P(t) = t^2 + 10t + 16 which looks like a regular quadratic. So, you factor it normally:

You get P(t) = (t+8)(t+2)... you get 8 and 2 since 8*2=16 and 8+2 = 10

Now, re-substitute t = x^2:
(x^2+8)(x^2+2)