Difference of Two Squares

Overview:

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

Prerequisite materials:

Factorising quadratics;
Multiplying out a pair of brackets.

Proof:

Left to right;

Right to left.

Example problems:

With algebra
- Simple
- Complex

With integers

Questions

Further study and reading:

Sum of two squares;
Difference of two cubes;
${\cos }^2\theta -{\sin }^2\theta$.