Evaluate the trigonometric function.Round your answer to four decimal places.
$\tan \left( - \frac { \pi } { 8 } \right)$
A)0.5858
B)-0.4142
C)0.0858
D)2.5858
E)1.5858

Question

Evaluate the trigonometric function.Round your answer to four decimal places. 
 $\tan \left( - \frac { \pi } { 8 } \right)$  
A)0.5858
B)-0.4142
C)0.0858
D)2.5858
E)1.5858

Quizplus · Accepted Answer

The tangent of a negative angle is the negative of the tangent of the angle, so $\tan \left( - \frac { \pi } { 8 } \right) = - \tan \left( \frac { \pi } { 8 } \right)$. The exact value of $\tan \left( \frac { \pi } { 8 } \right)$ is not commonly memorized, but using a calculator or trigonometric identities, we find that $\tan \left( \frac { \pi } { 8 } \right) \approx 0.4142$, thus $\tan \left( - \frac { \pi } { 8 } \right) = -0.4142$.

Evaluate the Trigonometric Function tan⁡(−π8)\tan \left( - \frac { \pi } { 8 } \right)tan(−8π​)

Evaluate the Trigonometric Function $\tan \left( - \frac { \pi } { 8 } \right)$