Question

How do you factor `a^4+b^2`?

Answer 1

`a^4-b^2 = (a^2-ib)(a^2+ib)`

Explanation:

This can be treated as a difference of squares:

`A^2-B^2 = (A-B)(A+B)`

by putting `A=a^2` and `B=ib`, where `i^2=-1`...

`a^4-b^2 = (a^2)^2-(ib)^2 = (a^2-ib)(a^2+ib)`