How Form 8655 Circular 2024

Okay, I did a video about the unit circle. I just filled in the top right quadrant. People have asked me to do the rest of it, so I guess here we go. Here's a way to remember the unit circle or a couple tricks to at least help you along the way. Again, the unit circle is a circle of radius 1, so this is 1. Okay, we're just plotting points, everybody can do this. Negative 1 and negative 1. Okay, and remember that the circumference of a circle is 2 pi times its radius. Well, the unit circle has radius 1, so we'll just get 2 pi times 1 or simply 2 pi. We measure angles again from the positive x-axis. We measure positive angles counterclockwise, so that means the distance around the circle is 2 pi. Again, people, you know if you do, if you turn around on a skateboard, you don't do 2 pi radians, you do a 360. Okay, so 360 degrees is equivalent to 2 pi. Okay, so if we go the entire way around the circle, we'll go from zero degrees to equivalently 2 pi degrees, well half of 2 pi would be pi radians. I said degrees to PI degrees, that's wrong, it's PI radians and 2 pi radians. Excuse me, there is thinking about skateboarding so pi radians that's going to correspond to the point negative 1 because when we're over at an angle of Pi or equivalently 180 degrees, we're at negative 1. Okay, so let me speed this little faster. PI over 2, 3 PI over 2 at the bottom. And think about it, it's 1 PI over 2 to PI over 2, which is PI, 3 PI over 2, 4 PI over 2, which is 2 pi. Okay,...