Question

What is the difference of two squares method of factoring?

Answer 1

There's a single formula which refers to "difference of squares":

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

If we use FOIL we can prove that. Difference of squares method would refer to doing something like the following:

`x^2 -1 = (x - 1)(x+1)`
`x^2 - 4 = (x-2)(x+2)`

Or even the double application here
`x^4 - 16 = (x^2)^2 - 4^2 = (x^2 - 4)(x^2 + 4) = (x-2)(x+2)(x^2+4)`