Post #23

This week we went over the practice ap test we took last week.... here are some concepts that i am starting to understand a little bit better:

lim h->0

ln(2+h)-ln2/h... the easiest way to do this problem is to just take the derivative of ln2. To do that you must treat 2 as x. So it becomes lnx. The derivative of lnx is 1/x. Now you just plug 2 back into the x value and you get 1/2.

Those table problems are not that bad anymore either:

They want to know the average rate of change of function f on [1,4]. To work this problem you have know know the average rate of change formula which is f(b)-f(a)/b-a. We know b is 4 and a is 1. So you look on the table, find 4 under the x column, look over at the f column and find what 4 equals there, it is equal to 6. Do the same for 1, it equals 2. So you set up your equation, 6-2/4-1 which equals 4/3.

There are also some problems that you will have to use the first derivative on. If they ask you for a relative max, then you have to either find the first derivative of the function or sometimes they give you the derivative of the function. You would solve for x to find your critical values and set them up into intervals. Then you would plug in numbers between those intervals into the function. To have a relative max, the intervals have to go from positive to negative. If none of the intervals do that, then the answer would be none of these.

What i'm still having trouble with:

1. Numbers 10-12 on the non-calculator portion.
2. Numbers 16,19 and 20 on the non-calculator portion.
3. Numbers 31, 32 and 36 on the calculator portion.

See you all tomorrow :)