What is the value of sin (5π / 6) ?

1)

2)

3)

4) 150

Solution: Choice C is correct.

Sin(5π/6) = sin(π- π/6) = sin(π/6) = ½.

Alternate Solution:

Sin(5π/6) = sin (150°)  ( by substituting π radians = 180°)

Now 150° lies in the second quadrant, and sin is positive in second quadrant.

Therefore, options A and B can be ruled out.

Also the value of sin always lies between -1 and 1.

Therefore option D can be ruled out.