Question 80735: If theta is an acute angle such thatsin theta=5/13, what is the value of sin 2theta
Answer by stanbon(75887)   (Show Source):
You can put this solution on YOUR website! If theta is an acute angle such that sin(theta)=5/13, what is the value of sin (2theta)
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If sintheta=5/13, y=5 and r=13; Find x: x^2=r^2-y^2; x=sqrt(13^2-5^2)=12
Then cos(theta)=12/13
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sin(2theta)=2sin(theta)cos(theta)
=2(5/13)(12/13)
=120/169
=0.71
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Cheers,
Stan H.
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