Question

Find the value of $\sin {765}^{\circ }$

Answer 1

It is known that the values of $\sin x$ repeat after an interval of $2\pi$ or ${360}^{\circ }$
$\therefore \sin {765}^{\circ }=\sin (2\times {360}^{\circ }+{45}^{\circ })$

$=\sin {45}^{\circ }$

$=\frac{1}{\sqrt{2}}$