Sin210° =
a)-sin210°
b)-sin30°
c)sin(-210°)
d)sin30°

Option B (-sin 30°)

Step-by-step explanation:

Sine function is one of the trigonometric functions. Sine function is regarded as an odd function, which means that f(-x) = - f(x). Also, sine function is positive in the first two quadrants and negative in the last two quadrants. 210° lies in the third quadrant since 210° is greater than 180°. Therefore, the basic angle or the reference angle of 210° is 210° - 180° = 30°. We already know that sin 30° = 0.5. This means that whenever the angle is between 180° and 360°, the output of the sine function is negative. Therefore, sin 210° = -0.5. Only answer B is the correct option since -sin 30° = -0.5.

step-by-step explanation: