#Find limits graph
262 messages ¡ Page 1 of 1 (latest)
!status
What step are you on?
1. I don't know where to begin.
2. I have begun but got stuck midway.
3. I got an answer but I was told that it's wrong.
4. I got an answer and would like my work checked.
5. I have a question about someone else's work/solution.
6. I have completed the problem and don't need help anymore. Thank you.
7. None of the above
step #1
what have you tried
puting in an answer, But i got it wrong**..**
im not sure who he is**..**
He asked you on what step you are
@light sequoia
Step #1
They doesnt seem to respond
oh**.**
Ok do you know what a limit is?
not really**..**
That would be a good start to find out. Do you have any notes or resources on it?
n**-no.**
In short, a limit examines what does a function look like as it's gets really close a certain point without actually getting to the exact point
How did you get assigned this problem without a book or notes to refer to?
idk**..** đ˘
Do you understand this?
not really**..**
This is saying, what does the function's y value get really close to as its x value gets really close to -6
So here's the graph around -6
what is the y value approaching as the x value gets close to -6?
not sure**..**
do your finger
on the graph
and follow it
until 6
and look at the y-axis
at which y value would your finger be if you approach -6
im confused**..**
Look at the x value â-6â
What y value is there when x = -6
Thatâs like the most basic way I can say it
Do you know what we mean when we say "x value" and "y value"? Do you know what the x and y axes are?
sort of**..**
Ok do you know where -6 is on the x axis?
y**-yes..**
Do you see the line above -6?
yes**..**
Imagine a straight line that goes from the line above -6 all the way to the y axis
What y axis value do you get? Closest to
4**?**
Thatâs your answer
This is how you read the coordinates of a point
and as you approach x -> -6 the more you go near y -> 4
this is what I meant by following the graph with your finger
up until x = -6
so you get an idea of what approaching means

at least it's making you think, so I take that as progess as opposed to "I don't know"
notice
Iâll go through the first one:
The first one is saying the limit as x approaches -6, from the left side. Look at the graph starting from the LEFT, and approach -6, whatâs the value of the y axis when you approach from the left

@forest epoch
You see the left side right?
yes**..**
Do you see how x is -9, at the very left?
yes**..**
Okay follow that line until it ends, you see how it ends up at -6?
What y value is when the line gets to -6? Again create a straight line
i miss your anime gifs
im confused**..**
-4?
Yes thatâs from the left side
**-**7
Yes
how would I solve this one**?**
Since you have 2 different answers to where x approaches -6, the limit does not exist
how would I find this on a graph**?**
f(-6) is just asking what the y coordinate is on the graph where itâs defined
And in this case it wants us to look at the closed circle, which = -4 on the y values
Okay I wonât be here to assist you for every problem
Just know when it says âx -> (âvalueâ) itâs saying, when x that âvalueâ, what is y
When x approaches 0 from the left side, y is -5
Another example is
lim f(x) x -> 0^+
What is y when x approaches 0 from the positive side? -5 again
Therefore the limit when x -> 0 converges to -5 and therefore does exist
I canât walk you through it fully anymore, you have to try
I can answer questions
@forest epoch
ok**..**
Sorry if I sounded mean but i can answer questions you have
ok**..**
wdym by when it "does exist" ?
Limits can only exist if y is the same value when x approaches that number from both left side and right side
There are other scenarios where occasionally one-sided limits can exist but donât worry about that
If a limit is -5 from the left, and like -7 from the right, then it doesnât exist
If itâs -5 from both left and right, it exists
This refers to the overall limit so on a graph, go to x = 0 and find what value âyâ is when x is 0, when you find the line or point, identify if it approaches that same y value from both sides
Example here for the first one:
lim: x -> 0^- means what value is y when x is 0? From the left (or negative side)
In this case, the answer is -5, since from the left side, the line approaches y = -5.
im confused**..**
If you donât mind me asking but what grade are you in?
because calculus could be pretty hard if you donât know what Iâm saying
or in school are you learning it?
12th grade**..**
i just started learning it in school**..**
i haven**'t learn this type of math before..**
Oh
yeah**..**
not sure**..**
When it says 0+, it means 0 from the positive side (right, in red)
When it says 0-, it means 0 from the negative side (left, blue)
Do you understand?
i think so**..**
Right now, just look at x -> 0 as x = 0
The question is asking, when x = 0 on the graph, what is y?
X is horizontal line, Y is vertical line
@forest epoch It may be confusing since 0 isnât there on the horizontal line, but 0 is between -1 and 1, itâs the place where both lines intersect?
No the limit does exist
I made this
Green highlight = Y axis
Yellow highlight = X axis
When going along the yellow highlighted one, in the middle thatâs where 0 is at, known as x = 0.
@forest epoch can I elaborate?
sure**.**
Now that we know where x = 0 is, go along the green highlight (make sure x is still 0), when we go down, we see that the line goes to -5, this is called y = -5
We see that, when we go down on the y axis, we get -5
And as we can see, the line goes to y = -5 on both sides, so the limit does exist from the left and right side
wait**..** isnt left supposed to be âŹ ď¸ and right would be âĄď¸ ?
Yea the direction, but weâre calling ârightâ and âleftâ as points on the graph
Okay, the right side of the graph is everything above 0 (1 to 10)
And the left side is everything below 0 (-1 to -10)
So when we say âas x approaches 0 from the right sideâ weâre going from the right side until we reach x = 0, then after we stop and see if there is any y values on x = 0.
f(x), when you replace x with a number, which is 0, youâre asking; what value is y, when x is 0?
Itâs basically the same as the limit question, but not rlly. anyways look at x = 0
There is only one line that touches the y axis, where x is 0
Hint: itâs from before
-5?
Firstly can you mark x = 3?
Ok now create a vertical line (top to bottom) at x = 3
And tell me y value that little open circle at x = 3 equals to
Now look at the y-axis, what value is the open circle?
3**.**
Itâs negative 3 since (-) means negative
And on the y axis, anything lower than 0 is negative
Y axis is top to bottom
oh**.**
i've read it wrong**..**
đ
Before solving the limit question, look at the line at -3, does it act the same?
Like Iâm saying, does the âlineâ or function behave the same when itâs near x = 3, the right and left side?
uhm**..**
im not sure**..**
From the right side, you can try putting your finger on the line and following it until it reaches x = -3
Do it with the left, and tell me did your finger go in the same direction from both sides?
y**-yes..**
Then tell me, does the limit exist or not?
Given what ive previously said about limits existing
y**-yes..** it does exist**...**
Thatâs right, and since it does exist, the answer for all 4 should be the same
limit: x -> 3 from the right side, what is the y value?
We did this earlier, and itâs -3
And since the right side = left side here, that means itâs -3 from the left side too, which means the limit also does exist, and f(3) is -3
Are you starting to understand it more?
Here
a little bit**..**
Tell me when youâre on the next problem
The first 3 questions are the same answer,
Since the limit does exist, you donât need to put DNE
Try to do this one on your own, when you think youâre finished send me all your answers and Iâll check it
This one is like the previous one
do I do the same thing**?**
Yes itâs the same thing like the other one, but different numbers
would f (2) = 2**?**
is it -2?
For which one? All of them?
the 1st one**..**
Itâs just 2, when x = 2, the y value is 2, itâs not -2 (as you can see by the line)
Ok now observe the line from the positive side, once you reach x = 2, what value is ur finger point to, on the y axis? Is it the same? is it different?
wdym by that**?**
is it from the x-axis ?
Move your finger across the line, but when you reach x = 2 (X AXIS), you look at the y axis
What y axis value do you get
2**.**
Thatâs right
And since the left side and right side is the same, the function indeed exists
When the function exists, the limit is the same as the ones you got previously (whether itâs right or left side), theyâre both the same anyways.
Yes now the other one is 2
Oops I forgot to mention that an open circle means either less or greater than
So yes itâll be undefined at that specific point
Itâs almost 12am sorry
Open Circle: less or greater than
Closed Circle: less, greater than, OR equal to
its ok**..**
⢠When a function approaches the same y value from both the right and left, then the limit is defined. Given this, the limit for left & right side will be equal.
⢠When a limit approaches 2 different y values at a given x value, the limit does not exist (DNE)
⢠Open Circles: either less or greater than, cannot be equal to.
⢠Closed Circles: less, greater, and is able to be equal to.
⢠Left side (negative x values)
⢠Right side (positive x values)
⢠Y Axis (Horizontal: top to bottom)
⢠X Axis (Vertical: right to left)
This is basically all the rules so far
I donât think you know what continuity is yet, correct?
@forest epoch
n**-no..**
Okay you donât have to worry about it until your school teaches you it, but continuity is how continuous a function is
A discontinuity means a breakage in continuity in the function
@forest epoch any more problems?
So youâre leaving?
Itâs almost 12am for me too
y**-yes..**
i need to go to sleep**..**
i dont want to stay up**..**
Okay goodnight if you learn anything new at school I can help you with it
ok**.**
I**'ll probably work on this math problem tomorrow.**
If I have any questions**,** I**'ll ask for help..**
This one is a different and harder than the other ones
So yea thatâs fine
Bye
bye Rel !
Nevermind just analyzed the problem itâs essentially the same
Ok ok bye now have a great night
you too**,** Rel !
I
