prove: sinx + sin(2x) + sin(3x) = sin(2x)(1+2cosx) thanks!
Last edited by phthiriasis; June 14th 2008 at 05:58 PM.
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Originally Posted by phthiriasis prove: sinx + sin(2x) + sin(3x) = sin(2x)(1+2cosx) thanks! Here's one way to do it: the key step is realizing that and applying the sum and difference formula: Now, factor.
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