# Trigonometry Examples

First, split the angle into two angles where the values of the six trigonometric functions are known. In this case, can be split into .

Use the sum formula for cosine to simplify the expression. The formula states that .

The exact value of is .

The exact value of is .

The exact value of is .

The exact value of is .

Multiply by to get .

Simplify .

Multiply and to get .

Combine using the product rule for radicals.

Multiply by to get .

Multiply by to get .

Simplify .

Multiply and to get .

Multiply by to get .

Combine the numerators over the common denominator.