Wednesday, April 1, 2009

Factoring with the difference of squares

I think factoring is something which becomes internal, you see a problem, make a guess, and then check. The best method is trial and error till it becomes intuitive.

Still the difference of squares method is often taught, and so I will show it here.

Basically the difference of squares is always factored in the following form:


Which equals (x2 - y2)


x2 - 9

9 is a perfect square so we can use the memorized formula


Again, I prefer gaining an intuitive understanding of factoring, but memorizing a rule like this can help till you gain an intuitive understanding.

No comments: