SOLUTION: Evaluate using double angle formulas: cos 22.5 degrees

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Question 549619: Evaluate using double angle formulas:
cos 22.5 degrees
Answer by Alan3354(69443) About Me  (Show Source):
You can put this solution on YOUR website!
cos 22.5 degrees
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cos%28t%2F2%29+=+sqrt%28%281+%2B+cos%28t%29%29%2F2%29
= sqrt%28%281+%2B+cos%2845%29%29%2F2%29
A half-angle formula, actually.