Convert into radians and then express entirely in terms of the sine of an angle…

MATHEMATICS · Subjective · CBSE · Mathematics · Trigonometric Functions · Trigonometric Functions

Problem

Convert

126^{\circ}

into radians and then express

\cos 126^{\circ}

entirely in terms of the sine of an angle measured in radians that lies between

-\dfrac{\pi}{2}

and

\dfrac{\pi}{2}