Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

**SlowlyFading****Member**- Registered: 2012-06-12
- Posts: 149

17) should be

Except there should be a minus sign between the two 2's..18) should be

19) should be

I'm just here to get some help with an online math course I'm taking.

Offline

**noelevans****Member**- Registered: 2012-07-20
- Posts: 236

Hi SlowlyFading!

Hey, you are using LaTex! That's fantastic. Takes a little bit of getting used to but it's worth it.

17) What are (5-6) and (-2+2)? And notice that the x term is just -3x. Nothing combines with it.

Looking at the LaTex for your answer to 17) I can't figure out why the 2x^2 and 2x got stuck

together.

18) Check!, OK, Correct, Right, Correctomundo!

19) Looking at the LaTex I can't figure out why the extra x got stuck to the 4x^2 term.

Anyway without that extra x (should be a space where the x is) the answer looks good:

Notice that the \; causes the spaces in the LaTex output. The more you put, the wider the space.

Help bobbym! Can you help us figure out what the problem is with the LaTex?

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).

LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi;

2x^2 2x

On 17 he has a . instead of a plus or a minus. Latex can not interpret it.

4x^2 x

Same problem on 19.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,960

Hi Bobby and noelevans,

My browser's not displaying the dot in SlowlyFading's post.

I think the problem is that the apparent minus sign is actually an 'em dash', which MIF's LaTeX can't interpret (but Codecogs displays it as if it were a minus sign).

When composing in M$ Word, a minus sign is automatically replaced by an em dash after typing a space followed by a minus sign followed by a space and some other entry. So I wonder if SlowlyFading's composition was in a word processor, not a LaTeX editor. That problem doesn't arise when typing directly into MIF's message box.

With the em dash in I get:

#17:

#19:

Using a minus sign instead of the em dash gives:

#17:

#19:

Composing in M$ Word without using a space on both sides of the minus sign displays correctly.

Also, when typing directly into MIF's message box the display is the same with and without spaces before and after the plus and minus signs.

*Last edited by phrontister (2012-08-15 13:51:34)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi phrontister;

You might be right. That is the reason I type directly into codecogs. Saves a lot of problems. Even using latex from M can be a problem.

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,960

Hi Bobby,

If you click on SlowlyFading's #19 you'll see the different dash lengths between "2 - x" and "x - 4". #17 doesn't have that comparison, but you can see the dash is longer than usual...like in #19's "2 - x".

*Last edited by phrontister (2012-08-15 14:18:05)*

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi phrontister;

I can edit the length of those dashes to be equal but how will that get rid of that "."?

**In mathematics, you don't understand things. You just get used to them.**

**I agree with you regarding the satisfaction and importance of actually computing some numbers. I can't tell you how often I see time and money wasted because someone didn't bother to run the numbers.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,960

I can't see that "." even though I've wiped my specs ten times already! .

Where exactly is it?

"The good news about computers is that they do what you tell them to do. The bad news is that they do what you tell them to do." - Ted Nelson

Offline

**noelevans****Member**- Registered: 2012-07-20
- Posts: 236

Thanks all of you!

I can't see the "." in the original post, but I can see the difference in the lengths of the dashes, the

minus vs the m dash. I do my encoding with "Post reply" on MIF so I guess that's why I haven't nad

any problems with it.

Thanks again!

SlowlyFading, did you see the difference in the two dashes?

Writing "pretty" math (two dimensional) is easier to read and grasp than LaTex (one dimensional).

LaTex is like painting on many strips of paper and then stacking them to see what picture they make.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi phrontister;

Could be that is how my browser's font interprets that character.

His post #26 when I click on his latex

x4 + 4x^3 + 2x^2 2x

there is that darn dot.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,732

hi bobbym,

That'll be it. I see no dot with IE9.

I've long known about the minus sign problem.

If I take someone's text version of a question and paste it back in [latex] brackets the minuses don't show.

But if I retype them they do. I can set it up on my keyboard too. Make a text minus, copy it into Latex and it vanishes. Type it inside the square brackets and there it is. Weird.

His latex: -4x^3 + 4x^2 x - 4

Now re-minused:

Bob

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi;

Got it. There is the dot!

**In mathematics, you don't understand things. You just get used to them.**

Offline

**bob bundy****Moderator**- Registered: 2010-06-20
- Posts: 6,732

Excel says the ASCII for a long minus is 150 and a short is 45.

When I type one on my keyboard it is a 45, but when it is rendered into Latex it becomes a 150.

Try a character for 150 and 45 on your computer and see what it shows.

B

You cannot teach a man anything; you can only help him find it within himself..........Galileo Galilei

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,960

Hi Bobby,

Got it. There is the dot!

I always believed that you saw it, but not necessarily that it was there!

I'd thought that maybe there was a fly-spot on your screen, or that you wore binocular specs and had them on back-to-front!

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi Bob;

I get a û when I enter alt 150. On mine this does not render in latex at all. Did you mean alt 95?

Hi phrontister;

I'd thought that maybe there was a fly-spot on your screen, or that you wore binocular specs and had them on back-to-front!

I killed those flies about a month ago. Yes, I got both of them. The question is, to dot or not to dot. Post #37 shows an actual, in living color snapshot of my screen. The dot according to my computer is a real phenomena and not an apparition.

I always believed that you saw it, but not necessarily that it was there!

It is true that my dopamine and/or serotonin levels have been dropping over the last few months but why would that make my computer see dots?

**In mathematics, you don't understand things. You just get used to them.**

Offline

**phrontister****Real Member**- From: The Land of Tomorrow
- Registered: 2009-07-12
- Posts: 3,960

bobbym wrote:

...but why would that make my computer see dots?

Maybe its stress levels are up?

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,821

Hi bobbym

the alt+150 isn't necessarily the same character as the ASCII 150 character.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Maybe its stress levels are up?

I did not think of that. I will have it hum a pleasant tune while displaying an aquarium screensaver. That should calm it down.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,821

No, that is what would cqlm you down. I think it needs a circuit masaage.

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

Hi;

http://www.keepandshare.com/doc/947949/ … on-windows

This here page says I am entering the ascii characters correctly.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,821

Did you try the first 31?

Either way, searching through the table, I found that the short and the long dash are 45 and 196 respectively.

*Last edited by anonimnystefy (2012-08-16 02:23:12)*

Here lies the reader who will never open this book. He is forever dead.

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

For those this table is different than the special character table but after that they seem the same.

**In mathematics, you don't understand things. You just get used to them.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,821

Hi bobbym

Did you see the edit?

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline

**bobbym****Administrator**- From: Bumpkinland
- Registered: 2009-04-12
- Posts: 92,264

I sure did. Now what?

**In mathematics, you don't understand things. You just get used to them.**

Offline

**anonimnystefy****Real Member**- From: The Foundation
- Registered: 2011-05-23
- Posts: 15,821

Just asking. Did you see my suggestion of a circuit massage for your computer?

Taking a new step, uttering a new word, is what people fear most. ― Fyodor Dostoyevsky, Crime and Punishment

The knowledge of some things as a function of age is a delta function.

Offline