# Trigonometry Examples

Step 1

Start on the left side.

Step 2

Step 2.1

Rewrite as .

Step 2.2

Rewrite as .

Step 2.3

Since both terms are perfect squares, factor using the difference of squares formula, where and .

Step 2.4

Apply pythagorean identity.

Step 2.5

Multiply by .

Step 3

Apply Pythagorean identity in reverse.

Step 4

Subtract from .

Step 5

Apply Pythagorean identity in reverse.

Step 6

Step 6.1

Simplify each term.

Step 6.1.1

Apply the distributive property.

Step 6.1.2

Multiply by .

Step 6.1.3

Multiply by .

Step 6.2

Subtract from .

Step 7

Rewrite as .

Step 8

Because the two sides have been shown to be equivalent, the equation is an identity.

is an identity