Question

k

Answer 1

One sec
Let me post the right pic

Answer 2

this confuses me O.o

Answer 3

what part

Answer 4

Well, if x was 0, what would he top be aproaching and does the bottom go the same way?

Answer 5

The absolute value signs should be a huge clue in this case.

Answer 6

so which one do you think?

Answer 7

I know which it is, but based on those two clues, what do you think?

Answer 8

i was thinking either A or D more on d?

Answer 9

Yes, D, dne. The top is going to -8, but the bottom MUST be + becase of the abs val, so -* and anything positive is a jump discontinuity.

Answer 10

A is also out because of the abs val. No way to get -4 out of an absolute value.

Answer 11

what about this ? @e.mccormick

Answer 12

Again, this is one where you can actually try the number. The limit of the top is 8+10 because it is heading towards that. The bottom is 10-8 because it is heading towards that. If those two answers are equal, there is a limit. Otherwise, DNE.

Answer 13

When you have a full limit, you are looking at the limit from the left and the limit from the right. If they match, there is a limit. No match, no limit.

Answer 14

I was thinking A at first

Answer 15

im not at all sure about this one

Answer 16

Because of the limit part saying\[\lim_{8 \rightarrow 8}\]

Answer 17

Argh. x->8.

Answer 18

So I am right?

Answer 19

No, but I want you to get why. Just put 8 in for x and see what you get in both equations.

Answer 20

one I get 18 and one I get 2

Answer 21

So, do they match? If yes, the limit exists. If no, it does not exist.

Answer 22

so then would that me DNE or 2 because it says < 8 and the other > or = 8 they do not match DNE it is

Answer 23

And if they match, that is the limit.

EXACTLY! Now you are getting it.

Answer 24

The way you would see it in a textbook is something like: The limit of the x < 8 is the left hand limit, or - limit. The x > 8 os the right hand limit or + limit. And the + and - must match or DNS.

Answer 25

or DNE... DNS is an intenet thing. LOL.

Answer 26

LOL Im thing DNE for this one too because the middle equation does not match at all :/

Answer 27

how can they all be DNA that makes me nervous lol

Answer 28

Now this one has an = on its own. That did not happen before. Just so you know, the = part does not matter in limits. Why? because the limit is where are you going to. = is where are you at!

That means the only important parts are the top and bottom.

Answer 29

And yah, I think they should have given you an assortment.

Answer 30

well those match and that confuses me is it DNE or not ? because the top and bottom met the x < 5 , X > 5 criteria

Answer 31

5-5=0, 8=8, and 5+3=8, so they are trying to trick you into thinking 8 because the middle and bottom match. However, limits are not about where you are at, the 8 for x=5 is a trick in this one.

Answer 32

Now, if you ignore the trick, you are asking if the top and bottom match. So does 0 = 8, which is no. So you are right, DNE.

Answer 33

Visually, a system of equations is something like this:
http://www.math.ucdavis.edu/~kouba/CalcOneDIRECTORY/limconsoldirectory/limits.gif

What they are doing is turning that into a bunch of little formulas then asking you questions about it. Sometimes people work better if they sketch a quick graph. Sometimes they are OK witht he calculations. Depends on the person.

Answer 34

YOURE GGGRRRRRREAT

Answer 35

In that picture I linked you, -1 and 2 DNE. But 1 is a limit at that point. Even though 1=3, the limit at 1 is 2. That make sense? And thanks.

Answer 36

yes

Answer 37

Good. I hope you have less trouble now. If you have more than one way to remember it, it is more likely that you will remember. So visually and calculations both, make some notes that put both in your words, and months later you can get this.

Answer 38

okie dokie

Answer 39

And trust me, you will need it later. By the end of calc 1 you think you are done with limits. Nope. They come back in Calc 2 to haunt you.

Answer 40

hate em lol

Answer 41

Hehe, Well, they actually come in handy when you see them as integrals. But that makes them easier to use.... then you go back to them.