Answer
$\theta =\sin ^{-1}\left( \dfrac {1}{3}\right) \approx 0.34+2\pi k$
Work Step by Step
$3\sin ^{2}\theta -7\sin \theta +2=0$
$\sin \theta =\dfrac {7\pm \sqrt {7^{2}-4\times 2\times 3}}{2\times 3}=\dfrac {7\pm 5}{6}=2;\dfrac {1}{3}$
$sin \theta $ can not be greater than 1 so
$\theta =\sin ^{-1}\left( \dfrac {1}{3}\right) \approx 0.34+2\pi k$
