Evaluate the Trigonometric Function Using Its Period as an Aid $\cos \frac { 17 \pi } { 4 }$

Multiple Choice

Evaluate the trigonometric function using its period as an aid.
$\cos \frac { 17 \pi } { 4 }$

A) $\cos \frac { 17 \pi } { 4 } = \sqrt { 2 }$
B) $\cos \frac { 17 \pi } { 4 } = - \frac { \sqrt { 2 } } { 2 }$
C) $\cos \frac { 17 \pi } { 4 } = \frac { \sqrt { 2 } } { 2 }$
D) $\cos \frac { 17 \pi } { 4 } = - \sqrt { 2 }$
E) $\cos \frac { 17 \pi } { 4 } = \infty$