Question

4. Evaluate the following Trigonometric Functions giving exact values and explain how you found your answer.A. cos (- 120°)B. Tan 5pi/6

Answer 1

PART A:

Determine the value of trigonometric expression.

`\begin{gathered} \cos (-120)=\cos (120) \\ =\cos (90+30) \\ =-\sin 30 \\ =-(1)/(2) \end{gathered}`

PART B:

Determine the value of trigonometric expression.

`\begin{gathered} \tan ((5\pi)/(6))=\tan (\pi-(\pi)/(6)) \\ =-\tan (\pi)/(6) \\ =-\frac{1}{\sqrt[]{3}} \end{gathered}`