5.4 MultipleAngle Identities - Amphitheater Public Schools Multiple angles ID...Solve sinx + sin3x =...
Transcript of 5.4 MultipleAngle Identities - Amphitheater Public Schools Multiple angles ID...Solve sinx + sin3x =...
5.4 Multiple angles ID comp.notebook
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5.4 MultipleAngle Identities
There are several double angle formulae that we need to know:
sin2x=
cos2x=
tan2x=
5.4 Multiple angles ID comp.notebook
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Ex. 1Solve cos2x=sinx on [0,2π)
TRYSolve sin2x=2sinx on [0,2π)
5.4 Multiple angles ID comp.notebook
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Ex. 2Solve sinx + sin3x = 0
Express cos4x using double angles.
TRY with a little help :)
Solve cos2x + cos4x = 0
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Power Reducing IdentitiesCommon power reducing identities are:
sin2x=
cos2x=
tan2x=
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Ex. 3With the aid of the power reducing identities prove that
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HalfAngle identitiesAnother set of useful identities are:
Ex. 5
Evaluate cos 15o without a calculator.
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Ex. 4Solve