lim notation

shahar

shahar

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1584614736637.png
1. What is the expression with lim say in the picture? What is the expression suppose to be?
2. How can I formulate a mathematical question with that notation? (for instance)
 
O.K. thank you.
someone else?
Or is it just only have a reason in the painter (of the picture) mind?
 
shahar said:
O.K. thank you.
someone else?
Or is it just only have a reason in the painter (of the picture) mind?
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It's possible that this is a typo. Writing it out as text you would have lim x -> a f(x) = f(a).

-Dan
 
shahar said:
View attachment 17264
1. What is the expression with lim say in the picture? What is the expression suppose to be?
2. How can I formulate a mathematical question with that notation? (for instance)
Click to expand...
It looks to me like a non-mathematician's attempt to mimic math. I wouldn't take it as a reliable reference for notation, any more than I'd take your writing as a reliable source for English grammar (or mine for Hebrew).

EDIT: In particular, I think they are just random expressions and equations, and are not meant to be related. What is the source?
 
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topsquark said:
It's possible that this is a typo. Writing it out as text you would have lim x -> a f(x) = f(a).
Click to expand...
Agreed. My first reaction was that the \(\large{5x}\) is totally out of place.
Given \(f(x)=x^2=1\) then \(\mathop {\lim }\limits_{x \to 3} f(x) = f(3) = {(3)^2} - 1 = 8\)
I wish it were an admonition against just plugging in to evaluate a limit. Maybe it is?
 
[MATH]\lim_{x \rightarrow a} f(x) = f(a)[/MATH]
merely means that f(x) is continuous at x = a. It is more a qualitative statement than a quantitative one.

It means that f(x) has a value close to or equal to f(a) if x is close enough to a.
 
It looks to me that it is saying that if \(f(x)=x^2-1\) then \(\mathop {\lim }\limits_{x \to 3} f(x) = 8\)

and that \(\mathop {\lim }\limits_{x \to a} f(x) = f(a) \)
 
Jomo said:
It looks to me that it is saying that if \(f(x)=x^2-1\) then \(\mathop {\lim }\limits_{x \to 3} f(x) = 8\)

and that \(\mathop {\lim }\limits_{x \to a} f(x) = f(a) \)
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It could be, but it never mentions 3 at all. That's why I'm expecting that when we are told the source, it will not turn out to be showing any particular problem, but just an illustration that says, "look at all this random math shooting across!" I could be wrong, of course.

And, of course, the question was about the notation, which we all agree is wrong in using ">" instead of an arrow.
 
Dr.Peterson said:
It could be, but it never mentions 3 at all. That's why I'm expecting that when we are told the source, it will not turn out to be showing any particular problem, but just an illustration that says, "look at all this random math shooting across!" I could be wrong, of course.

And, of course, the question was about the notation, which we all agree is wrong in using ">" instead of an arrow.
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I used the limit to make a connection between x^2-1 and 8
 
But if your theory does not explain all the data, including the 5x, then it isn't convincing. My theory, that it's not meant to fit together in the first place, explains all the data.

In any case, I don't think this is meant to be a puzzle, and I think we've answered the question, which was about notation.

Again, we don't know what the picture means until @shahar tells us about its context!
 
It from tips to academic learning. It's just a picture.
The article is about how to deal with the problem about the difficult to understand the material of the level that start in the beginning of the learning in the universities in Israel.
If some of you want I can write its tip.
That is only a tip of how to deal with . I don't know why the editor of the web (that is belong the commonest daily newspaper in Israel that call Yedihot Haronut(="Last reports/news" [this is just a brand name, its include the all the part of news paper).
The web is called ynet. (means - Yedihot-net).
Here is the source:
www.ynet.co.il

עשרה דברים שהלוואי שהייתי יודע לפני שהתחלתי ללמוד מדעים מדוייקים

מתחילים ללמוד מדעים מדוייקים? ברכותיי! אתם בוודאי נרגשים ומצפים לתחילת הלימודים. כל ההתחלות קשות, וכדי לגרום להתחלה שלכם להיות קלה יותר הכנו עבורכם עשר עצות. למרות שעצות אלו אינן מופיעות בידיעונים של המחלקות, אני מאמין שהן הדבר החשוב ביותר שמישהו יגלה לכם בשלב הזה
www.ynet.co.il www.ynet.co.il
When I read the some comment of the site (it said that the web block entering from outside of Israel to the web, but you can't try). If you want I can bring the tip here by my description and language.
 
I think it's clear that my impression was correct: it is merely an illustration, and is meant only to represent "scary math".

Some television programs (I'm thinking of Nova in America) show screens full of complicated math to represent such things, but usually, as far as I can tell, they are genuine (and much more complicated) calculations, but not necessarily relevant to the topic being discussed!

In any case, don't expect to learn from such an illustration!
 
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