My question is ¿ QUESTION: 5 X 2 + 7* ?

Do you actually have a question about symbols?
If so please state it clearly.
 
pka said:
Do you actually have a question about symbols?
If so please state it clearly.
Click to expand...

That is the question; 5 X 2 + 7* = [the answer?]


I think the question could be ring theory and/or hyperreal numbers; but I am not sure?

[I guess you could try and solve it any way that you think is possible]


There wasn't any instruction[-s] given with the question.


I tried to look up the asterisk symbol " * " on that https://en.wikipedia.org/wiki/List_of_mathematical_symbols page

so as to ascertain how to solve the problem but I am still not sure...

Any help would be appreciated...
 
Filetmignon9797 said:
That is the question; 5 X 2 + 7* = [the answer?]
I think the question could be ring theory and/or hyperreal numbers; but I am not sure?
[I guess you could try and solve it any way that you think is possible]
There wasn't any instruction[-s] given with the question.
I tried to look up the asterisk symbol " * " on that https://en.wikipedia.org/wiki/List_of_mathematical_symbols page
so as to ascertain how to solve the problem but I am still not sure...
Click to expand...
If you are reading an article or a textbook that contains that question it should have defined the *.
Your are correct that in non-standard analysis the * is used for some hyper-real numbers.
But, I have never seen it used in that way. In fact that usage makes no sense.
Here is a fee non-standard calculus. You can get the whole of just chapters.
An Infinitesimal Approach by Jerome Keisler in chapter 3, there is good proof of this. The chapters and whole book is a free down-load at http://www.math.wisc.edu/~keisler/. But I don't remember that usage.
If you find it please post it.
 
pka said:
If you are reading an article or a textbook that contains that question it should have defined the *.
Your are correct that in non-standard analysis the * is used for some hyper-real numbers.
But, I have never seen it used in that way. In fact that usage makes no sense.
Here is a fee non-standard calculus. You can get the whole of just chapters.
An Infinitesimal Approach by Jerome Keisler in chapter 3, there is good proof of this. The chapters and whole book is a free down-load at http://www.math.wisc.edu/~keisler/. But I don't remember that usage.
If you find it please post it.
Click to expand...


The question itself was taken off of a Canadian brain teasers form and the full question itself is as follows:

SKILL TESTING QUESTION: 5 X 2 + 7* / QUESTION D’HABILITÉ : 5 X 2 + 7*



In the meantime I shall look through that Calculus textbook to see whether or not I can solve the problem, though...
 
Filetmignon9797 said:
¿ QUESTION: 5 X 2 + 7* ?


¿I am not sure whether this is ring theory and/or hyperreal numbers?

¿Any help so as to solve the problem would be appreciated?
Click to expand...
I think we need to know the source of the question, as notation often depends on context. Is there anything in the context about hyperreal numbers, for example? And if there is no context at all, then there is no question. (In fact, this doesn't look like a question at all, but an expression of some sort. A question needs words, too.)

An image of (or link to) the original would help. As it is, I can't even be sure whether "X" means a variable or a set or an operation, for example.
 
Dr.Peterson said:
I think we need to know the source of the question, as notation often depends on context. Is there anything in the context about hyperreal numbers, for example? And if there is no context at all, then there is no question. (In fact, this doesn't look like a question at all, but an expression of some sort. A question needs words, too.)

An image of (or link to) the original would help. As it is, I can't even be sure whether "X" means a variable or a set or an operation, for example.
Click to expand...


Filetmignon9797 said:
The question itself was taken off of a Canadian brain teasers form and the full question itself is as follows:

SKILL TESTING QUESTION: 5 X 2 + 7* / QUESTION D’HABILITÉ : 5 X 2 + 7*
Click to expand...



¿I guess there could be multiple ways to solve the problem?


¿I am not sure whether you would use infinitesimals and/or the extension principle to solve that problem?



According to page 27 and page 28 of 42 http://www.math.wisc.edu/~keisler/chapter_1b.pdf


¿As to the extension principle for hyperreal number[-s]; I am not sure, but maybe with considering what the natural extension of 7* is?;


¿I am not sure what the natural extension of 7* is?; possibly....


¿ 7*= could be either 7^0= [which equals 1] and/or 7^1 = [which equals 7] and/or 7^-1 = [which equals 0.142857143] ?


since ¿"Every real number is a member of R*, but R* has other elements too. The infinitesimals in R* are of three kinds: positive, negative, and zero"?


"page 24 of 42 http://www.math.wisc.edu/~keisler/chapter_1b.pdf"


{¿that covers the requirement for a positive, the requirement for a negative, and the requirement for zero?}


¿So I guess you could write the answer as an inequality?


¿ 5 X 2 + 7^0 [which equals 1] = [which equals 11] and/or 5 X 2 + 7^1 [which equals 7] = [which equals 17]

and/or 5 X 2 + 7^-1 [which equals 0.142857143] = [which equals 10.142857143]?

{¿that covers the requirement for a positive, the requirement for a negative, and the requirement for zero?}


¿ When R is the answer; then R would be?


¿ 17 ≥ R ≥ 10.142857143 ?


Without the instructions;

[the worksheet isn't graded and didn't have any instructions; I think it is more to test your capacity for problem solving];

¿ I am not sure whether or not my answer is correct but am I on the right track though?

¿ Does what I just wrote make any sense?
 
Last edited:
Filetmignon9797 said:
The question itself was taken off of a Canadian brain teasers form and the full question itself is as follows:

SKILL TESTING QUESTION: 5 X 2 + 7* / QUESTION D’HABILITÉ : 5 X 2 + 7*
Click to expand...

I think you're going far beyond what I would call a "brain teaser", or a "skill testing question" as described here. There is nothing in this context to suggest that the ideas you are stretching for could be relevant. If it's a mathematical symbol at all, it would have to be the complex conjugate, but not in this context.

It really would be helpful if you showed an actual image, so we could see whether the X is a multiplication, and how the * is printed.
 
Dr.Peterson said:
I think you're going far beyond what I would call a "brain teaser", or a "skill testing question" as described here. There is nothing in this context to suggest that the ideas you are stretching for could be relevant. If it's a mathematical symbol at all, it would have to be the complex conjugate, but not in this context.

It really would be helpful if you showed an actual image, so we could see whether the X is a multiplication, and how the * is printed.
Click to expand...


When some people may or may not call it a "complex conjugate" I don't necessarily think that is how you should approach it.


It is true that....

"
z* means the complex conjugate of z. from https://en.wikipedia.org/wiki/List_of_mathematical_symbols

{
{\bar {z}}
can also be used for the conjugate of z, as described below.) complex conjugate / conjugate / complex numbers

(3+4i)^{\ast }=3-4i
. "


But, The way the order of operations is presented for the question is as follows: QUESTION: 5 X 2 + 7*

¿With that outline[-ing] and/or chart[-ing] you should perform the asterisk operation prior to the multiplication operation?.....

When taking that into consideration and taking into consideration ¿"Every real number is a member of R*, but R* has other elements too. The infinitesimals in R* are of three kinds: positive, negative, and zero"? on "page 24 of 42 http://www.math.wisc.edu/~keisler/chapter_1b.pdf" ?

¿I think I could have answered the question correctly by using an inequality to represent L* ?


¿The only other possible way to solve the question I can guess from what I first hypothesized would be to replace the negative and the positive values for * in 7* with ∞ and/or -∞ respectively [which is the mathematical symbol for infinity and infinitesimals]?


¿ 5 X 2 + 7^0 [which equals 1] = [which equals 11] ?

¿ and/or 5 X 2 + 7^∞ [which equals 7] = [which simply equals 5 X 2 + 7^∞] ?

¿ and/or 5 X 2 + 7^-∞ [which equals 7] = [which simply equals 5 X 2 + 7^-∞] ?


¿ When L is the answer; then L would be?


¿So the final answer would be? = ¿ 5 X 2 + 7^∞ ≥ L ≥ 5 X 2 + 7^-∞ ?


¿ I changed the unknown variable for my final answer to L so as to avoid confusion?.....


¿ Any feedback would be appreciated?....
 
I'm sorry, but this is all nonsense. None of it can be what is intended. But since you choose not to show what it actually looks like, as I asked, there's nothing I can do to help.
 
You must log in or register to reply here.
Top