Q. $\sin{120{^\circ}}\cos{150{^\circ}} - \cos{240{^\circ}}\sin{330{^\circ}}$ is equal to
A) 1
B) $- 1$
C) $\frac{2}{3}$
D) $- \left( \frac{\sqrt{3} + 1}{4} \right)$
Explanation
(b)
$\sin{120{^\circ}\cos{150{^\circ} - \cos{240{^\circ}\sin{330{^\circ}}}}}$
$= {- cos}{30{^\circ}\sin{60{^\circ} - \cos{60{^\circ}\sin{30{^\circ}}}}}$
$= - \sin{(60{^\circ} + 30{^\circ})} = - 1$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.