Post 26

So today is Wednesday, not Sunday, but this is my post 26. Better late than never.

Anyway, last week before B-rob left, we went over a few things that were bothering us about the AP tests. We did two days of hard core review, and it was really helpful. Some of the things that were bothering me included limits, and derivatives of integrals when the bounds have variables.

First of all, I was a little confused about how limits worked when the bottom turned out to be zero. One thing you can do for this is to factor and cancel. Also, if when the number is plugged in and you get zero over zero, you can use L’Hopital’s Rule. For this rule, you can take the derivative of the top and the bottom separately and try to plug in until you get a number instead of zero over zero.

For derivatives of integrals I knew the derivative of the integral canceled each other out, but I didn’t know what to do when the bounds had variables in them. I learned that you plug in the b variable then solve. For example if a problem asks to take the derivative of S from 0-x^2 of sin(t), this is how you do it

First, the derivative and the integral cancel each other out, so you just plug in only your b bounds

sin(x^2) then you have to remember to multiply by the derivative of the insde X 2x

= 2xsin(x^2)

Knowing this will help a lot on the AP now.

Some things I still don’t understand include particle problems. We go over these time and time again in class, and I seem to understand them when we’re going over them, but on the test, I don’t know, it seems like they change or I forget. Help?