- #1

- 356

- 7

## Homework Statement

Evaluate the following exactly.

cos 300°

sin(-120°)

## Homework Equations

Unit circle

## The Attempt at a Solution

I seem to have a problem with the remembering if it is going to be the position on the unit circle such as in these cases I thought it was

cos 300°= 5∏/3 but it is actually I think 1/2 so I got the problem wrong

then you have

sin(-120°) = 4∏/3 but this is wrong and I think it is -√3 / 2 so yeah then I got this one right

csc120°= 2√3 / 3

I just never know when I am supposed to use which one for the exact value. Could someone help out please?