Question

How do you factor `n^4 - 1`?

Answer 1

`(n-1)(n+1)(n^2+1)`

Explanation:

By using this formula `a^2-b^2 = (a-b)(a+b)`

here we have `a = n^2` and `b = 1`

`(n^2)^2 - 1` (remember `(a^n)^m = a^(nm)`)

`(n^2-1)(n^2+1)`

You do it again with `(n^2-1)(n^2+1)` and you have your answer