AP Calc: Week 28ish - New Trimester!

Finally into the third trimester. It feels good to be on the last leg of my high school career, but graduating is also an intimidating idea. As for math, chapter seven is our final chapter, and we are plowing our way through it. We have been learning about what happens if you have an area of a graph closed off by bounds and rotate it around an axis. By rotating it around an axis, we get a shape, and we are trying to find the area of that shape. We have learned two methods of finding this area, the shell method and the disc method. From my understanding, (which could be completely wrong), the disc method is for when we are going around an axis in, lets say, y, we would solve it in terms of y. We use the disc method when it's hard to solve for the variable, so its the opposite of whatever axis we are revolving it around. So if it was around the x axis, we would solve it in terms of y. Most problems can be solved either way, but not all of them. I actually find the shell method way easier. However, I feel like when the test comes around I am going to get them mixed up, since the two methods are very similar!