SOLUTION: i need to evaluate/compute cos^2(pi/8)-sin^2(pi\8) thanks

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Question 675953: i need to evaluate/compute cos^2(pi/8)-sin^2(pi\8) thanks
Answer by lwsshak3(11628) About Me  (Show Source):
You can put this solution on YOUR website!
i need to evaluate/compute cos^2(pi/8)-sin^2(pi\8)
identity: cos(2x)=cos^2(x)-sin^2(x)
..
cos^2(pi/8)-sin^2(pi\8)=cos[2*π/8]=cos(π/4)=√2/2