How do you find the value of $sin2theta$ given $costheta=1/3$ and $0<theta<90$ ?

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Answer 1 · 2018-05-19T21:27:59

$= (4sqrt(2) ) / 9$

$sin^2 theta + cos^2 theta = 1$

$=> sin theta = sqrt(1 - cos^2 theta )$

$=> sin theta = (2sqrt(2) ) / 3$

$sin 2 theta = 2 sin theta cos theta$

$= 2 * 1/3 * ( 2sqrt(2) ) / 3$

$= (4sqrt(2) ) / 9$

How do you find the value of sin2thetasin2theta given costheta=1/3costheta=1/3 and 0<theta<900<theta<90?