SOLUTION: Can you help me please; Given sin (x+y) = sin x cos y + cos x sin y and cos (x+y) = cos x cos y -sin x sin y ; Derive a formula for cos (2x).
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-> SOLUTION: Can you help me please; Given sin (x+y) = sin x cos y + cos x sin y and cos (x+y) = cos x cos y -sin x sin y ; Derive a formula for cos (2x).
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Question 984815: Can you help me please; Given sin (x+y) = sin x cos y + cos x sin y and cos (x+y) = cos x cos y -sin x sin y ; Derive a formula for cos (2x). Answer by Alan3354(69443) (Show Source):
You can put this solution on YOUR website! cos (x+y) = cos x cos y -sin x sin y ; Derive a formula for cos (2x)
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cos(x+x) = cos(x)*cos(x) - sin(x)*sin(x)
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