Question

Match the graphs of the functions on the left with the graphs of their derivatives on the right.

Answer 1

Do you know what the derivative of a 2nd degree function is?

Answer 2

no

Answer 3

You know the following I guess:
If f is decreasing, then f' is negative (and vice versa).
If f is increasing, then f' is positive ( and vv).

Answer 4

yes

Answer 5

No look at the first graph on the left.
To the left of the y-axis, it is decreasing, to the right it is increasing.

Answer 6

yes it does

Answer 7

This means, for f' you are looking for a function that is negative on the left side of the y-axis and positive on the right.

Answer 8

ok

Answer 9

so it will be #2 in the second attachment?

Answer 10

I can see it on one of your drawings on the right! Do you?

Answer 11

Yes it will be number 2 ?

Answer 12

so to will have letter A

Answer 13

No, I've got C

Answer 14

but you can't match a with c , it says to match the left with the right so it has to be a letter with a number

Answer 15

I mean this (see image)

The parabola on the left (2nd degree function) has the straight line on the right as it's derivative.

Answer 16

so number one will be 1 with letter c?

Answer 17

I meant number 2 sorry

Answer 18

so 2C ?

Answer 19

Yes

Answer 20

okay

Answer 21

Now try #2.
See what it does: increasing, decreasing, increasing.
So you're looking for a graph that is +, then -, then +.

Answer 22

i thought we already did number 2

Answer 23

?

Answer 24

He was telling you number #1 is C. There musta been some confusion there c:

Answer 25

ohhh okay lol sorry

Answer 26

so number 2 will be f?

Answer 27

@zepdrix: thx

Answer 28

Yes!

Answer 29

okay :)

Answer 30

I think you got it!

Answer 31

number 3 looks funny

Answer 32

I think #2 is `e` actually :o hmm

Answer 33

It is down, up, down, up, so look for -,+,-,+

Answer 34

okay so number 3 will be A ?

Answer 35

@zepdrix : you're right, I'm having trouble looking at three different pictures, @onegirl: sorry ;)

Answer 36

okay thanks for the correction zep

Answer 37

so 3A ?

Answer 38

Yes, 3A

Answer 39

okay

Answer 40

so number 4 will be D?

Answer 41

Right again! Always decreasing, so looking for a derivative that is always negative...

Answer 42

okay

Answer 43

so i'm guessing number 5 will be 5B?

Answer 44

?

Answer 45

You guessed wrong...
Look at graph #5 and compare with #3

Answer 46

It behaves in the same way: dec, inc, dec, inc, so -,+,-,+

Answer 47

ok so it will be 5f

Answer 48

Oops, look something went wrong with my last response.

Because 5 and 3 behave in the same way, you have to choose the same derivative: 5A

Answer 49

ohh ok

Answer 50

so letter A goes to two graphs? okay

Answer 51

That's the mean part of the question ;)

Answer 52

okay so how about the last one number 6?

Answer 53

It goes down, then up, then down, so for f' we have: neg, pos, neg

Answer 54

so it will be 6B

Answer 55

No, that goes a lot more from - to + etc.

Answer 56

(it is really simple)

Answer 57

ohh so it will f since it does go negative pos then neg

Answer 58

Yes, it's 6F.
I must admit this kind of question can be confusing, because you constantly have to switch from increasing , decreasing to +, -.

Answer 59

okay well thanks for your help