Find the Value of Given Trigonometric Function $\tan \frac { \pi } { 8 }$

Multiple Choice

Find the value of given trigonometric function.Round your answer to four decimal places.​ $\tan \frac { \pi } { 8 }$ ​

A) $\tan \frac { \pi } { 8 } \approx$ 0.3142
B) $\tan \frac { \pi } { 8 } \approx$ 0.6142
C) $\tan \frac { \pi } { 8 } \approx$ - 0.4142
D) $\tan \frac { \pi } { 8 } \approx$ 0.4142
E) $\tan \frac { \pi } { 8 } \approx$ 0.5142