Find the Point $( x , y )$ On the Unit Circle That Corresponds to the Real Number

Multiple Choice

Find the point $( x , y )$ on the unit circle that corresponds to the real number $t = \frac { 5 \pi } { 4 }$ .Use your results to evaluate $\tan$ .

A) $\tan t = \frac { \sqrt { 2 } } { 2 }$
B) $\tan t = 0$
C) $\tan t = - \frac { \sqrt { 2 } } { 2 }$
D) $\tan t = 1$
E) $\tan t = \text { undefined }$