[ 3 / biz / cgl / ck / diy / fa / ic / jp / lit / sci / vr / vt ] [ index / top / reports ] [ become a patron ] [ status ]
2023-11: Warosu is now out of extended maintenance.

/sci/ - Science & Math

View post   
File: 6 KB, 149x22, question1.jpg [View same] [iqdb] [saucenao] [google]
5021733 No.5021733[DELETED]  [Reply] [Original]

Hate to ask for help with basic CS homework but I'm stumped. How many elements are in this set? Pic Related, its the set. Dumping wallpaper in return.

>> No.5021740
File: 228 KB, 1600x1000, 1327979079815.jpg [View same] [iqdb] [saucenao] [google]
5021740

>> No.5021742
File: 157 KB, 1440x900, 1330314220574.jpg [View same] [iqdb] [saucenao] [google]
5021742

>> No.5021754

4

>> No.5021758

>>5021754
Yup

>> No.5021761
File: 78 KB, 1366x768, 1327976634530.jpg [View same] [iqdb] [saucenao] [google]
5021761

Why?

>> No.5021795
File: 832 KB, 500x255, cutey_Emma-2.gif [View same] [iqdb] [saucenao] [google]
5021795

Probably 4.
Maybe 3, depending on the model (i.e. 1={0} is a standard definition, so in that case...).

http://en.wikipedia.org/wiki/Peano_axioms#Set-theoretic_models

>> No.5021841

I was wondering, since <span class="math">\emptyset[/spoiler] is an element of every set, if that implied an extra element, but apparently it does not count towards the size of the set in cardinality

>> No.5021844

It appears to be a set of four elements of which one is an element, one is a sub-set with one element, one is a sub-set with one element and a sub-set with one element, and one is a subset with no elements.

>> No.5021847

1 is element number one.
The set containing 1 is element number two.
The set containing 1 and the set containing 1 is element number 3.
The null set is element number 4.

Count 'em up like separate objects.

>> No.5021851

>>5021841
The empty set is a SUBSET of every set.
>>5021761
Lets list the elements:
>1,
>{1} is another,
>{1,{1}} makes three,
>and finally {0}.
As >>5021795 pointed out, 1 is usually defined as {0}, so they could be the same element, but chances are if you don't even know how many elements are in that set, then that fact is probably beyond you.

>> No.5021853

>>5021841

No you fucking idiot, the empty set is a SUBSET of every set, not an ELEMENT of every set.

LRN 2 MATH

fucking ridiculous.

{1,{1},{1,{1}},{O}}

REMOVE OUTER BRACKETS:

1,{1},{1,{1}},{O}

HIT RETURN AT THE FIRST COMMA:

1,
{1},{1,{1}},{O}

HIT RETURN AT THE NEXT COMMA:

1,
{1}
{1,{1}},{O}

DO NOT HIT RETURN FOR COMMAS INSIDE OTHER BRACKETS:

1,
{1}
{1,{1}}
{O}
THE FUCKING ANSWER IS FOUR.

>> No.5021860
File: 381 KB, 475x547, yoda.jpg [View same] [iqdb] [saucenao] [google]
5021860

>>5021853

>> No.5021865

>>5021853
In which semester does one learn the comma-technique?

>> No.5021875

>>5021865
The comma-technique is what oldschool C-hackers use to hack into CSV files. The worst fear of hardworking Excel users.

>> No.5021952
File: 148 KB, 1920x1200, 1331336837511.jpg [View same] [iqdb] [saucenao] [google]
5021952

You guys are the bomb, thanks alot.

>> No.5021959

>>5021841
>empty set is an element of every set
>there can be infinite empty sets
>all sets have infinite elements

>> No.5021965

>>5021959
>there can be infinite empty sets

No, there is only one empty set. That's the easiest theorem of set theory - it falls right out og the axioms.

>> No.5021976

>>5021847
its not the null set, its a set containing the null set

>> No.5021978

>>5021952
Np, but please don't post those wallpapers next time.

>> No.5021994
File: 148 KB, 641x522, All Questions.jpg [View same] [iqdb] [saucenao] [google]
5021994

Here is all of it if you wanted to see...

>> No.5022002 [DELETED] 

What would you recommend?

>> No.5022009

>>5021978
What would you recommend?

>> No.5022023

>>5022009
Not posting them.
If your thread is science/math related (like yours), people will probably respond anyway.

>> No.5022033

>>5022009
posting better ones. or space stuff. space stuff is like boobs on /b/, it's always related.

>> No.5022041

Does the answer change wether it's set theory or comp sci?

Intuitively I would think it's 1. Because 1 is the only element...

Is this just like, "the computer would read this as having 4 elements" or something?

>> No.5022045

>>5022023

This. It also makes it annoying to read through the thread. Oh and all of your wallpapers suck dick anyway.

A Dr. House quote implying that religious people have no reasoning abilities? Nigga you just went full edgy.

>> No.5022162

>>5022041
No, this set has 4 elements mathematically too, unless you are taking 1 to be {0}, in which case it has 3.
1 is clearly not the only element; it also contains {1} (different to 1), {1,{1}} (also a different set entirely) and {0}. If you were only concerned in what sets are left when you look 'inside' all the sets then there would be no sets! As I mentioned earlier, 1 is defined as {0} - all mathematics is build from the empty set!

>> No.5022176

>>5022162

So does this mean that the set {1,{1},{{1}},{{{1}}}} has 4 elements as well?

And if so, are the elements in the set equal? If we're referring to |R then aren't all the elements in the set corresponding to the exact same thing?

>> No.5022184

>using 'null set' instead of 'empty set'

This isn't measure theory, seriously, stop.

>> No.5022188

>>5022176

The set contains four distinct elements.

>> No.5022190

Another question, how do you write

A = {n∈ℤ | n is a factor of 6}

in english?

>> No.5022194

>>5022190

The set of all integers divisible by 6.

>> No.5022199

>>5022176
1 != {1} != {{1}} and so on...
And elemens that show up more than once are actually the same.
So {2, 1+1, 3-1, 2, 4/2} has exactly one element.

>> No.5022201

>>5022194

correction - the set of all integers which divide 6.

>> No.5022235

>>5021875
One of the best things I've read on /sci/.

>> No.5022528

"Rewrite it by listing some of the elements

A = { x = 3n-7; x, n∈N; n < 5} "

um, what?

>> No.5022535

>>5022528
{ x = -4, -1, 2, 5}