SOLUTION: How to Verify this identity cos(x+y)+cos(x-y)=2 cos x cos y

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Question 1107546: How to Verify this identity
cos(x+y)+cos(x-y)=2 cos x cos y
Answer by stanbon(75887) About Me  (Show Source):
You can put this solution on YOUR website!
Verify this identity
cos(x+y)+cos(x-y)=2 cos x cos y
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[cosx*cosy-sinx*siny] + [cosx*cosy + sinx*siny]
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= 2cos(x)cos(y)
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Cheers,
Stan H.
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