SOLUTION: How to do Identities problems in Trig. Like Cos^2(pi/6)?

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Question 414084: How to do Identities problems in Trig. Like Cos^2(pi/6)?
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
remember:
cos+%280%29+=1
cos%2830%29+=+sqrt%283%29%2F2
cos%2845%29=+sqrt%282%29%2F2
cos%2860%29+=+1%2F2
cos%2890%29=+0

Also you must know that %28pi%29+=+180 degrees....so %28pi%29%2F6+=+180%2F6=30+
so, you will have
cos%5E2%28+pi%2F6%29+=cos+%5E2%28180%2F6%29=cos%5E2%28+30%29=sqrt%283%29%2F2%29%5E2