3. Rationalize the denominator:
Assume that the radicand is nonnegative.
4. Given that , express as a trigonometric function without radicals. Assume .
Use the sum or difference identities to evaluate exactly.
7. Assuming that and and that and are between 0 and , evaluate exactly.
8. Given that and that the terminal side is in quadrant II, find .
9. Given that and is in quadrant III, find and the quadrant in which lies.
10. Use a half-angle identity to evaluate exactly.
11. Given that and that ...