Mathematics
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OpenStudy (anonymous):
Find the exact value of sin(arctan(2)).
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OpenStudy (turingtest):
what triangle corresponds to arctan(2) ?
OpenStudy (anonymous):
it doesnt say but im assuming a right triangle
OpenStudy (turingtest):
yes, but which right triangle?
if we have\[\tan^{-1}(2)=\theta\implies\tan\theta=\frac{\sin\theta}{\cos\theta}=2\]
OpenStudy (anonymous):
so we are then left with sin(sin 2/cos 2)
OpenStudy (turingtest):
no, we want the arctan of 2. not tan of 2
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OpenStudy (turingtest):
remember the definitions of sine and cos
OpenStudy (anonymous):
so cos is on the top and sin on the bottom?
OpenStudy (turingtest):
why do you think that?
OpenStudy (turingtest):
do you know what arctan means?
OpenStudy (anonymous):
arctan is the opposite of tan
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OpenStudy (turingtest):
in a sense... arctan(x) is the angle t at which tan(t)=x
OpenStudy (turingtest):
I think you have confused it with the cotangent
OpenStudy (anonymous):
tan= opposite/adjacent so that 2/1
OpenStudy (turingtest):
yes
OpenStudy (anonymous):
then we have to find the hypoteneus so we can get the sin
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OpenStudy (turingtest):
exactly :)
OpenStudy (anonymous):
thats 2/sqrt5
OpenStudy (turingtest):
yep :)
nice job
OpenStudy (anonymous):
i see it makes since now. thank you!!
OpenStudy (turingtest):
welcome, happy to help