sin(-1290°)

sin(-1290°)

Using a trig identity, we have

sin(-1290°)  =  - sin(1290°)

First, express 1290/360 as a mixed number = 3 + 7/12

Disregard the "whole" part and multiply the fraction by 360

This gives 210...and sin(210) =  - (1/2)

But, we need the negative of this .... = 1/2

Of course.....putting the original thing into the on-site calculator would be faster ..... !!!!

you have to do you have to have a variable like 4 with it so it could be like 4*sin(-1290)