SOLUTION: (1+sin a)(1-sin a)=cos^2a

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Question 416004: (1+sin a)(1-sin a)=cos^2a
Answer by MathLover1(20850) About Me  (Show Source):
You can put this solution on YOUR website!
(1+sina)(1-sina)=cos^2a............on the left side is difference of

squares

a%5E2+-+b%5E2+=+%28a%2Bb%29%28a-b%29..use that

1-sin^2a=cos^2a

cos^2a=cos^2a