Find the Exact Value of the Expression If θ = $f ( \theta ) = \sin \theta \quad$

Multiple Choice

Find the exact value of the expression if θ = 45°. Do not use a calculator.
- $f ( \theta ) = \sin \theta \quad$ Find $3 f ( \theta )$ .

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