# Trigonometry Examples

Find the Exact Value cos(15)
Split into two angles where the values of the six trigonometric functions are known.
Separate negation.
Apply the difference of angles identity.
The exact value of is .
The exact value of is .
The exact value of is .
The exact value of is .
Simplify .
Simplify each term.
Multiply and .
Move to the left of .
Multiply and .
Move to the left of .
Combine the numerators over the common denominator.
The result can be shown in multiple forms.
Exact Form:
Decimal Form: