## haleyking345 Group Title Use a half-angle identity to find the evact value of each function. A.) Tan 165 degrees I have tried and cannot come up with the right answer. Can I have some help? one year ago one year ago

1. haleyking345 Group Title

Exact not evact sorry

2. tkhunny Group Title

2*165º = 330º = 360º - 30º Reference Angle -30º

3. exraven Group Title

$\tan \left( \frac{x}{2} \right) = \frac{\sin x}{1 + \cos x}$ plug x = 330º

4. haleyking345 Group Title

i did that, and i checked the answer in the back and it did not go right. I messed up somewhere but i do not know where.

5. exraven Group Title

maybe you forgot to rationalize the denominator?

6. tkhunny Group Title

Did you consider the quadrant? 330º is Quadrant IV (Tangent is Negative). 165º is Quadrant II (Tangent is negative) Please show your work and we'll be able to see where you wander off.

7. haleyking345 Group Title

|dw:1357957749155:dw|

8. tkhunny Group Title

@exraven wins. Just rationalize the denominator!

9. haleyking345 Group Title

how do you do that?

10. exraven Group Title

multiply by the conjugate

11. exraven Group Title

$\frac{-1}{2 +\sqrt{3}}$multiply by $\frac{2 -\sqrt{3}}{2 - \sqrt{3}}$

12. haleyking345 Group Title

the answer is square root 3 minus 2 in the book. I cannot quite get it to match

13. tkhunny Group Title

Again, let's see your work. We'll be able to tell where you wander off.

14. haleyking345 Group Title

|dw:1357958794041:dw|

15. exraven Group Title

yes, what is the value of square root of 9?

16. haleyking345 Group Title

3

17. tkhunny Group Title

That's it. Don't panic that it does not yet match the book. Keep going!

18. exraven Group Title

continue then

19. haleyking345 Group Title

|dw:1357959061747:dw|

20. exraven Group Title

yes, you got it

21. haleyking345 Group Title

Thank you