Question

How do I find the value of sin 5pi / 6?

Answer 1

sin `(5pi)/6`= `1/2`

Explanation:

Sin `(5pi)/6`= sin `(pi- pi/6)`= sin `pi/6`= sin 30 = `1/2`

Another way to think about it is to draw the angle in a Unit circle and create the "new" triangle in Quadrant II.

Drop a perpendicular to the x-axis and you will have the correct triangle to use.

From this triangle, you need the opposite leg length, which is `1/2`.
Since the hypotenuse is equal to 1 in the Unit circle, the opposite leg length is the answer for sine. (dividing by 1 is not necessary)