Question

ap calc ab help please !
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Answer 1

f' is the line of the slope of f

Answer 2

So on your first problem if you can find which line is positive when one is increasing and negative while the other is decreasing it's f'

Answer 3

How can I find that without an equation?

Answer 4

You can look at how line A decreases on the interval -infinity to zero

Answer 5

and then you can see that line b is negative from -infinity to zero

Answer 6

This problem is so confusing omg. Okay so is line B decreasing from .4- -infinit?

Answer 7

Yeah something like that

Answer 8

Really you just eyeball where one is negative and see if the other line is decreasing, and if the other is positive one is increasing

Answer 9

I think line B is positive and increasing while line A is decreasing

Answer 10

you can see that the straight line is the derivative because where its positive the arch is increasing and where its negative its decreasing

Answer 11

I'd just tell you the answer but I think its kinda important to understand. Give me a sec

Answer 12

ok thanks

Answer 13

Okay so I marked where line B is increasing / decreasing

Answer 14

You can see that line b is negative while a is decreasing

Answer 15

as well as positive while a is increasing

Answer 16

Yep so that would mean that it's f normal right

Answer 17

since the derivative is the line of the slope we know b is the derivative

Answer 18

Ohh ok

Answer 19

Do you get it? A is decreasing so the slope is negative, the slope of the line is the derivative. Look for the line that is negative while decreasing

Answer 20

Oh ok so you just find where it's decreasing and negative and if the slope is negative than it's the derivative

Answer 21

Yeah but it doesnt have to be decreasing AND negative, just decreasing.

Answer 22

oh ok i understand thanks for going through the work to help me with that one

Answer 23

Your next problem is about the definition of a derivative at a point which is defined by this http://archives.math.utk.edu/visual.calculus/2/definition.8/eq1.gif

Answer 24

Basically the number you want to find (the point) is a. So since you're finding 2, a is equal to 2.

Answer 25

So i would just try plugging them into the two definition of limit equations and see what comes out?

Answer 26

Not really your thing would look like (f(2+h) - f(2))/h

Answer 27

So for f(2+h) you plug (2+h) wherever you see x and f(2) where ever you see h for the 2nd part.

Answer 28

wait what 2nd part are you referring to

Answer 29

the - f(2)

Answer 30

Do you understand how to plug everything in?

Answer 31

You dont need to actually do it for this problem, but thats important because sometimes you do. Its kinda situational

Answer 32

im not sure i understand how to plug them in