Evaluate sine, cosine, tangent of -7pi/3 without calculator

[smsmith]

I do not understand where to begin with this:

Evaluate the sine, cosine, and tangent of -7pi/3 without using a calculator.

I tried completing the triangle using this number as angle but that just got more confusing. Any input would be great.

Thanks in advance!

 

[pka]

Because these two are equivlant: \(\displaystyle \frac{{ - 7\pi }}{3} \sim \frac{\pi }{3}\)

You do know the functions of \(\displaystyle \frac{\pi }{3}\), don't you?

 

[smsmith]

It appears as though I do not. That is the answer. However I am not terribly good at memorizing values. I do better when I know how the answer is reached.
Thanks again

 

[pka]

\(\displaystyle \frac{\pi }{3} \equiv 60^o\)
That is the measure of the angles in an equilateral triangle.

 

[smsmith]

I got it now.

Thank you again