What is the exact value of Sine-145pi/3?

[amy-lee]

I am stuck on this question.
What is the exact value of Sine -145pi/3?

I'm not sure if the work i did is right. I think i missed a step.

I think that the terminal arm of the angle is -pi/3 or -60 degrees. So since its negative than it would fall under quadrant 4. so sine= y/r
Sine -145pi/3=-root(3)/2

 

[tkhunny]

How did you not get a negative value for sine in Quadrant IV?

Excellent editing. Now we have it.

 

[Deleted member 4993]

I am stuck on this question.
What is the exact value of Sine -145pi/3?

I'm not sure if the work i did is right. I think i missed a step.

I think that the terminal arm of the angle is -pi/3 or -60 degrees. So since its negative than it would fall under quadrant 4. so sine= y/r
Sine -145pi/3=-root(3)/2 <<<< Looks good to me