# How do you factor #3u^4 - 19u^2 + 28#?

##### 1 Answer

Jun 4, 2015

If we allow irrational factors:

To find the factors for the factorization into

I basically tried a few combinations of the form

Having recognised that the quartic is a quadratic in

The factorizations into linear factors are a couple of examples of the general difference of squares identity: