Sin(x)=15 over17 and x terminates in quadrant 1 Find A) sin2x B) cos2x C) tan2x?
回答 (3)
2016-11-28 10:45 pm
sin^2+cos^2=1,,,(15/17)^2+cos^2=1
cos^2x=1-225/289=64/289,,,cosx=8/17
sin2x=2sincos=2(15/17)(8/17)=240/289
cos2x=cos^2-sin^2=(64/289)-(225/289)=
-161/289
tan2x=sin2x/cos2x=240/225
cos^2x=1-225/289=64/289,,,cosx=8/17
sin2x=2sincos=2(15/17)(8/17)=240/289
cos2x=cos^2-sin^2=(64/289)-(225/289)=
-161/289
tan2x=sin2x/cos2x=240/225
2016-11-19 7:16 pm
the reference triangle for x is { 8 , 15 , 17 } ..use this to work your problem
2016-11-19 7:10 pm
Use sin^2(x) + cos^2(x) to find what cos(x).
Then use the formulas for sin(2x) and cos(2x) in terms of sin(x) and cos(x).
tan(2x) = sin(2x) / cos(2x)
Then use the formulas for sin(2x) and cos(2x) in terms of sin(x) and cos(x).
tan(2x) = sin(2x) / cos(2x)
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