SOLUTION: Vertify is an identity cos^2(2x)+4sin^2(x).cos^2(x)=1

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Question 401382: Vertify is an identity
cos^2(2x)+4sin^2(x).cos^2(x)=1


Answer by Tatiana_Stebko(1539) About Me  (Show Source):
You can put this solution on YOUR website!
%28cos%282x%29%29%5E2%2B4%28sinx%29%5E2%2A%28cosx%29%5E2=1
%28cos%282x%29%29%5E2%2B%282%2Asinx%2Acosx%29%5E2=1
Use FORMULA 2%2Asinx%2Acosx=sin%282x%29
%28cos%282x%29%29%5E2%2B%28sin%282x%29%29%5E2=1
Use FORMULA %28sinx%29%5E2%2B%28cosx%29%5E2=1, so %28sin%282x%29%29%5E2%2B%28cos%282x%29%29%5E2=1
1=1