Can anyone tell me how the text arrived at the following answer?(adsbygoogle = window.adsbygoogle || []).push({});

cos 7pi/6 = -sqrt3/2

I just don't understand how to draw the triangle inside the unit circle and to visualize the cosine ratio in order to arrive at the answer(what are the lengths of the adjacent and hypotenuse?)..why is it negative too?

baby steps please?

thank you to anyone that can help.

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# Precalculus trig question?

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