Math Is Fun Forum

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Have you plotted anything yet?

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

Hi stefy,

I can't do that one. The second part is an imaginary number, and I've never done those.

You'll have to ask Bobby how M can do it.

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"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

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

No, I haven't plotted anything yet...in M or in anything else. Never got that far in school (unless I've forgotten it; but it would only have been very junior stuff).

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"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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Okay, simplest one is plot:

Plot[Sin[x]-Cos[x],{x,-5,5}]

try that one. Just to do one.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

Hi stefy,

I can't do that one. The second part is an imaginary number, and I've never done those.

You'll have to ask Bobby how M can do it.

Hi phro

I think you looked at the weong one. Looka at the one before it.

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“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.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Did you get a latex to run on your site?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

No. Haven't found an HTML encoding of the tag on the net.

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“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.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Did you ask MIF how he did it?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

Yes,but he said it was very hard to do. Plus,he uses FluxBB,unlike phpBB on mine. I think they might be somewhat different.

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“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.

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

How are you going to solve the problem?

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

I will look some more,maybe ask owners of other forums.

---

“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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

Hi Bobby,

Well, my first plot ever (I think) worked. Easy to copy & paste them.

I don't know what they do, or what they're good for. Probably for a better/different understanding of certain things through visual representation?

Off to work...

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"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

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

Hi stefy,

Please tell me post number of that problem to make sure I get the right one. Ta.

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"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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Hi phrontister;

Very good. Sometimes a visual aspect of an equation or a list of data points gives insight into them that is hard to get in any other way.

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

Hi phro

http://www.mathisfunforum.com/viewtopic.php?pid=213113#p213113

---

“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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

Hi stefy,

No, I can't get M to give any answer other than 0 (but I don't know much M - I'm fairly new at it). Maybe Bobby can.

This online high precision calculator gives an approximate answer (to 50 digits, rounded up), and a 10000-digit calculator (software) that I've got yields the same result, which is:

2.886751345948128798489482686275381e-17

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"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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Hi phrontister;

The question is made to make M fail. To make M work just go:

Sqrt[3.00000000000000010000000000000000]-Sqrt[3]

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

Hi phro

I was just trying to point out that M cannot do it. That is because it is not all powerful.

I must notice that you have learned much of the M syntax. More than I will ever.

Have you bought an M package or do you have a trial?

Stefy

---

“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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

Ah, good one. Nice trick, Bobby.

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"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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Or:

N[Sqrt[3+1/10000000000000000]-Sqrt[3],100] this forces M to go to exact rational arithmetic. Yields:

---

In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: sum of digit

The other way of doing it is discussed in the other thread.

---

“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.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

Something I just found:

Evaluate sqrt[3.0000000000000001], which yields 1.73205. Position the cursor after the 5, press the space bar and more decimal digits display: ie, 1.7320508075688772`

LB loses its way after 15 decimal places.

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"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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Hi;

You have a 6 in your display option. You can change it to more.

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.

phrontister

Real Member

From: The Land of Tomorrow

Registered: 2009-07-12

Posts: 4,822

Re: sum of digit

How do I do that? I can't find anything in the menus.

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"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

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: sum of digit

Edit->Preferences->Appearance->Numbers->Formatting

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In mathematics, you don't understand things. You just get used to them.
If it ain't broke, fix it until it is.
Always satisfy the Prime Directive of getting the right answer above all else.