Answer the following:

MATHEMATICS · Multi-part · CBSE · Mathematics · Trigonometric Functions · Trigonometric Functions

Problem

Answer the following: (a) Reduce

-\dfrac{89\pi}{6}

to its principal value lying in

(-\pi,\pi]

. (b) Hence, find (i)

\sin\!\left(-\dfrac{89\pi}{6}\right)

and (ii)

\cos\!\left(-\dfrac{89\pi}{6}\right)