Inverse Trig functions - due tomorrow!

Hey guys, I'm stuck on these 3 probs. I'll be trying to work on them for an hour or so, but I don't have any more time for them tonight. Any help MUCH appreciated. I tried the third one but got stuck, you would think the hint would help me out(d'oh!) Thanks for any help.

Evaluate the following without a calculator.

1. Sin^-1(sin11(pi)/14)

2. Cos^-1[Cos(7(pi)/5)]

3. Sin[2csc^-1(5/3)] Hint: Let csc^-1(5/3) = theta, then use the appropriate double angle formula.