## anonymous 2 years ago More trig/ Precal help

1. anonymous

Use an Addition or Subtraction Formula to find the exact value of the expression, as demonstrated in Example 1. $\tan(\frac{ -17\pi }{ 12 })$

2. anonymous

I think they may be referring to a trig identity like tan (s-t)=tan s - tan t/1 + tan s tan t?

3. anonymous

Yes it does refer to those identities. I can do that part of the problem, but what I don't really understand is how do you get to the point of for example: $\tan\frac{ \pi }{ 4} + \tan \frac{ \pi }{ 3 }$ or something like that

4. anonymous

They're supposed to be grouped I meant, tan ( pi/4 + pi/3 )

5. myininaya

$\tan(\frac{-17 \pi}{12})=\tan(\frac{-17 \pi}{12}+2 \pi)=\tan(\frac{-17 \pi +24 \pi}{12})=\tan(\frac{7 \pi }{12})$ $\tan(\frac{\pi}{3}+\frac{\pi}{4})$

6. anonymous

oh okay thank you so much