Question

Solve: ${\cos }^2{30}^0+{\sin }^{2}2x=1$

Answer 1

${\cos }^{2}30+{\sin }^{2}2x=1$

${\sin }^{2}2x=1-{\cos }^{2}30$

${\sin }^{2}2x={\sin }^{2}30$ (\since, ${\sin }^2\theta +{\cos }^2\theta =1$)

$2x=30$

$x={15}^{\circ }$