Math Is Fun Forum

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Set Symbols

A new page: Set Symbols

What do you guys think of it? Any mistakes?

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

bobbym

bumpkin

From: Bumpkinland

Registered: 2009-04-12

Posts: 109,606

Re: Set Symbols

Hi MIF;

Looks pretty good. I am not following how to get the complement of A as {1,9}.

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ShivamS

Member

Registered: 2011-02-07

Posts: 3,648

Re: Set Symbols

I think you defined C and D but forgot A. Although you only use A in 1 example so you can just write D complement instead.

Last edited by ShivamS (2014-11-17 13:34:24)

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Set Symbols

Good point, will amend.

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Jai Ganesh

Administrator

Registered: 2005-06-28

Posts: 48,406

Re: Set Symbols

Hi MathsIsFun,

I think the symbols/notations are exhausted! Great job!

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It appears to me that if one wants to make progress in mathematics, one should study the masters and not the pupils. - Niels Henrik Abel.

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anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Set Symbols

Hi MIF

Not sure if that's the general case, but I've seen the bolded "I" be used mostly for irrational numbers.

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MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Set Symbols

Has anyone else seen I used for irrationals?

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

Bob

Administrator

Registered: 2010-06-20

Posts: 10,621

Re: Set Symbols

hi MathsIsFun,

Good page.

: is also used to mean 'such that'.
http://en.wikipedia.org/wiki/List_of_ma … al_symbols

The complement of a set only has meaning if the 'universe' is defined.
http://en.wikipedia.org/wiki/Complement_(set_theory)

so you could have:   if U, the universe, = {1,2,3,4,5,6,7,8,9} and A = {2,3,4,5,6,7,8} then Asuperscriptc = {1,9}

There does not appear to be a regularly used symbol for the irrationals.  Wolfram and Wiki do not have one.  Maths Exchange has several suggestions (none of which I've ever seen used) but R−Q would seem to do the job.

Bob

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MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Set Symbols

Great, will add : and define a Universal Set for the Complement example.

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman

anonimnystefy

Real Member

From: Harlan's World

Registered: 2011-05-23

Posts: 16,049

Re: Set Symbols

Also, A\B can be used to mean A-B.

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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.

ShivamS

Member

Registered: 2011-02-07

Posts: 3,648

Re: Set Symbols

You might also want to include some symbols like the symmetric difference, relative complement and aleph-null.

Has anyone else seen I used for irrationals?

No, but neither have I seen "I" represent the "set of imaginary numbers".

There does not appear to be a regularly used symbol for the irrationals.

I believe the standard is R-Q. Q with a horizontal line on it, or R\Q.

Last edited by ShivamS (2014-11-18 07:26:28)

MathsIsFun

Administrator

Registered: 2005-01-21

Posts: 7,713

Re: Set Symbols

Thanks!

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"The physicists defer only to mathematicians, and the mathematicians defer only to God ..."  - Leon M. Lederman