Question

Check my answers?

Answer 1

1) Find the exact value: cos(7pi/12)
Part I: Find two common angles that either add up to or differ by 7pi/12. Rewrite this problem as the cosine of either a sum or a difference of those two angles.
Part II: Evaluate the expression.

2) tan(17pi/12)
Part I: Find two common angles that either add up to or differ by 17pi/12.
Part II: Evaluate.

3) sin(195 degrees)
Part I: pretty much the same as above
Part II: Evaluate.

4) cot(15 degrees)
Part I: Find two common angles that differ by 15 degrees. Rewrite this problem as the cotangent of a difference of those two angles.
Part II: Evaluate the expression.

Answer 2

OKAY. So for #1, I got:
\[\cos \frac{ \pi }{ 3 } + \frac{ \pi }{ 4 }\]
And for the answer, I got:
\[(\sqrt{2} - \sqrt{6})/4\]

Answer 3

I feel like it could be simplified further...

Answer 4

It is correct. No simplification required

Answer 5

Perfect, thank you! I'm pretty sure the rest are right, just want to make sure.

For #2:
Part I: \[\tan \frac{ 2\pi }{ 3 } + \frac{ 3\pi }{ 4 }\]
Part II: sqrt3 + 2

Answer 6

Correct

Answer 7

Thanks :)

#3
Part I: sin(135 + 60)
Part II: \[\frac{ \sqrt{2} - \sqrt{6} }{ 4 }\]

Answer 8

Correct

Answer 9

#4

Part I: cot(45 - 30)
Part II: sqrt3 + 2

Answer 10

All correct

Answer 11

Yay! Thank you :D