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Trig Identities s&d

Sum & difference & double angle identities

QuestionAnswer
sin2x 2sinxcosx
sin(x+y) sinxcosy + sinycosx
cos(x+y) cosxcosy - sinxsiny
cos(x-y) cosxcosy + sinxsiny
sin(x-y) sinxcosy - sinycosx
cos2x = cos^2x-sin^2x = 2cos^2x-1 = 1-2sin^2x
Created by: sarahdutton
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