Question

Find the values of the following: $\sin \left({-495}^o\right)$

Answer 1

$\sin (-{495}^o)=-\sin (360+{135}^o)$

$=-\sin \left({135}^o\right)$

$=-\sin ({180}^o-{45}^o)$

$=-\sin {45}^o$

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