SOLUTION: prove 2/(1+cos 2 t)= sec^2t

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Question 998935: prove 2/(1+cos 2 t)= sec^2t
Answer by josgarithmetic(39621) About Me  (Show Source):
You can put this solution on YOUR website!
Find, or derive, the double angle cosine formulas, and pick the one which uses only cos%28t%29. This is the one: cos%282t%29=2%2Acos%5E2%28t%29-1.

LeftHandSide

2%2F%281%2B2%2Acos%5E2%28t%29-1%29

2%2F%282%2Acos%5E2%28t%29%29

1%2Fcos%5E2%28t%29

and according to definition
sec%5E2%28t%29