How do you find the sine, cosine, and tangent of 19pi/2 radians?

1 Answer
Nov 5, 2015

sin((3pi)/2) = -1
cos((3pi)/2) = 0
tan((3pi)/2) = infinity/undefined

Explanation:

If we take away 2pi radians from the angle, it will still be the same angle. So, we do that until it is a more recognizable angle. Since (4pi)/2 is the same as 2pi, we will use that.

(19pi)/2 - (4pi)/2 - (4pi)/2 - (4pi)/2 - (4pi)/2 = (3pi)/2
Now to find the sin, cos, and tan values of (3pi)/2, use the unit circle.

sin((3pi)/2) = -1
cos((3pi)/2) = 0
tan((3pi)/2) = infinity/undefined
https://en.wikipedia.org/wiki/Unit_circlehttps://en.wikipedia.org/wiki/Unit_circle