Question

simplifiy sin(-960°)?

Answer 1

We can add multiples of 360 degrees to an angle and it wouldn't make any difference to its trigonometric ratio.
$\sin( - 960) \\ = \sin( - 960 + 360 \times 3 ) \\ = \sin( - 960 + 1080) \\ = \sin(120) \\ = \sin(180 - 120) \\ = \sin(60) \\ = \frac{ \sqrt{3} }{2}$

Answer 2

sin(-960°)

= - sin 960°

= - sin (11×90 - 30)

= - (-cos 30°)

= cos 30°

= √3/2 [Ans.]



Hope it will help you .