help me factorize p^4-1 as far as possible

\(p^4-1\) is a difference of squares. To make this clearer, the original expression can be rewritten as \(\left(p^2\right)^2-1^2\). Since the original expression is a difference of squares, it is possible to factor it via \((p^2+1)(p^2-1)\). Notice that one of the factors of the original expression is also a difference of squares, namely \(p^2-1\), so it is possible to factor even further. Therefore, the furthest factored expression would be \((p^2+1)(p+1)(p-1)\)