Factorise {a}^(4) - 16 ​

Question

Factorise

`{a}^(4) - 16`
​

Answer 1

Since both terms are perfect squares, factor using the difference of squares formula, a ^2 − b^ 2 = ( a + b ) ( a − b ) where a = a ^2 and b = 4 . ( a ^2 + 4 ) ( a + 2 ) ( a − 2 )