What is the difference of two squares method of factoring?

1 Answer
Mar 27, 2018

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) #