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

4. Evaluate the following Trigonometric Functions giving exact values and explain-example-1
User Harts
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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}

User Angeles
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