### Square of a Binomial

The Square of a binomial looks like

Think Pythagorean Theorem for the reason.

To obtain the correct value we need to FOIL. The meaning of is

**General Rule:**

**Example:**

Use this pattern to simply convert the square of a binomial without actually FOILing.

### Difference of Squares

This is called the \textbf{difference of squares} because the is squared, the is also squared, and they are subtracted (difference).

This happens when you multiply 2 special binomials.

**Example:** Foil the following

Notice the middle terms cancel out. The first term and last term are both perfect squares. They have subtraction in between them, hence the “difference” in **difference of squares**.

Thus, our answer is