HI! I couldn't really find any not confusing notes online so I just took a picture of my handwritten notes and I'll put it up here. If you can't read anything, for sure you can email me!
A point of clarification is that when there's a picture of a coordinate plane with a half circle, the half circle bit is the part of the unit circle you'll take your exact values from. So if it's not in those restrictions, it's either undefined or you can use a reference angle (I'm not totally sure how to deal with that yet). You can also always look and see if Kahn Academy has anything (hint:it does).
A point of clarification is that when there's a picture of a coordinate plane with a half circle, the half circle bit is the part of the unit circle you'll take your exact values from. So if it's not in those restrictions, it's either undefined or you can use a reference angle (I'm not totally sure how to deal with that yet). You can also always look and see if Kahn Academy has anything (hint:it does).