(sin^2 5п/3) / (sin^2 5п/4)

Решите задачу:

$\frac{ sin^{2} \frac{5 \pi }{3} }{ sin^{ \frac{5 \pi }{4} } } =( \frac{sin \frac{5 \pi }{3} }{sin \frac{5 \pi }{4} } ) ^{2} =( \frac{sin \frac{(6 \pi }{3}- \frac{ \pi }{3}) }{sin( \frac{4 \pi }{4}+ \frac{ \pi }{4} )} ) ^{2} =( \frac{sin(2 \pi - \frac{ \pi }{3})}{sin( \pi + \frac{ \pi }{4} )} ) ^{2} =( \frac{-sin \frac{ \pi }{3} }{-sin \frac{ \pi }{4} } ) ^{2} =$
$=( \frac{ \sqrt{3} }{2}: \frac{ \sqrt{2} }{2} ) ^{2} =( \frac{ \sqrt{3} }{ \sqrt{2} } ) ^{2} = \frac{3}{2} =1,5$