Find the Exact Value of the Expression If θ = $$f ( \theta ) = \cos \theta \quad \text { Find } f ( \theta ) \text {. }$$

Multiple Choice

Find the exact value of the expression if θ = 45°. Do not use a calculator.
- $$f ( \theta ) = \cos \theta \quad \text { Find } f ( \theta ) \text {. }$$

A) $\frac { \sqrt { 3 } } { 3 }$
B) $\sqrt { 2 }$
C) $\frac { \sqrt { 2 } } { 2 }$
D) $- \frac { \sqrt { 2 } } { 2 }$