## Search found 209 matches

- Sun Oct 14, 2007 9:57 pm UTC
- Forum: Mathematics
- Topic: Are there jordan curves with non-zero area?
- Replies:
**15** - Views:
**5536**

### Re: Are there jordan curves with non-zero area?

I have little knowledge in this area so forgive my misunderstandings. Isn't a hilbert curve non-overlapping?

- Sun Oct 14, 2007 2:26 am UTC
- Forum: Mathematics
- Topic: Are there jordan curves with non-zero area?
- Replies:
**15** - Views:
**5536**

### Are there jordan curves with non-zero area?

When one of the professors who specializes in a math field (I can't remember which one) related to this question was asked, he said "I don't know."

- Tue Oct 09, 2007 12:04 am UTC
- Forum: Mathematics
- Topic: (-1)^pi
- Replies:
**25** - Views:
**3288**

### Re: (-1)^pi

What can you say about negative numbers to powers of transcendental numbers? Mathematica, apparently, can't say anything. You may have to tell it to display the numerical result. Type (-1)^<ESC>pi<ESC> //N where <ESC> is the escape key. Nice, yes, thank you. OK, here are so more thoughts: -1 is rea...

- Mon Oct 08, 2007 11:04 pm UTC
- Forum: Mathematics
- Topic: (-1)^pi
- Replies:
**25** - Views:
**3288**

### Re: (-1)^pi

Rilian wrote:my calculator won't do (-1)^(2/3)

But I know that the answer is 1!

And matlab gives a retarded answer.

>> (-1)^(2/3)

ans =

-0.5000 + 0.8660i

That's a valid answer.

- Mon Oct 08, 2007 11:03 pm UTC
- Forum: Mathematics
- Topic: (-1)^pi
- Replies:
**25** - Views:
**3288**

### Re: (-1)^pi

Bluhhh, I feel retarded. -1 = e^(i*pi) so (-1)^pi = e^(i*pi^2)) = what you wrote. Why doesn't mathematica know this? For a second I thought I had stumbled upon something profound.

- Mon Oct 08, 2007 10:54 pm UTC
- Forum: Mathematics
- Topic: (-1)^pi
- Replies:
**25** - Views:
**3288**

### (-1)^pi

What can you say about negative numbers to powers of transcendental numbers? Mathematica, apparently, can't say anything.

- Thu Sep 27, 2007 2:35 pm UTC
- Forum: Mathematics
- Topic: Favorite Mathematical Equation
- Replies:
**87** - Views:
**21755**

### Re:

Sana wrote:Probably

Not sure why. It's just interesting I guess.

Yes this one is a classic, although I think

e^(i*pi) + 1 = 0

is better.

- Thu Sep 27, 2007 2:31 pm UTC
- Forum: Mathematics
- Topic: Graduate-Level Math Courses
- Replies:
**10** - Views:
**2655**

### Re: Graduate-Level Math Courses

I wouldn't really consider the monetary cost of the university. For every place I've checked out so far the math departments cover you 100% the whole way (or the first year for sure and after that depending on if you're making satisfactory progress).

- Tue Sep 25, 2007 6:25 pm UTC
- Forum: Mathematics
- Topic: Monkeys and Shakespeare
- Replies:
**32** - Views:
**4345**

- Sat Sep 22, 2007 6:27 pm UTC
- Forum: Mathematics
- Topic: When would you use the (various) canonical forms?
- Replies:
**11** - Views:
**2170**

- Fri Sep 21, 2007 3:57 pm UTC
- Forum: Mathematics
- Topic: Monkeys and Shakespeare
- Replies:
**32** - Views:
**4345**

- Thu Sep 20, 2007 4:45 pm UTC
- Forum: Mathematics
- Topic: Word Numbers Puzzle
- Replies:
**33** - Views:
**4444**

- Wed Sep 19, 2007 7:20 am UTC
- Forum: Mathematics
- Topic: Basic/Self-Evident Truth in Mathematics
- Replies:
**53** - Views:
**11994**

- Tue Sep 18, 2007 5:52 pm UTC
- Forum: Mathematics
- Topic: Favorite math jokes
- Replies:
**1452** - Views:
**494625**

- Mon Sep 17, 2007 12:55 am UTC
- Forum: Mathematics
- Topic: The 6 Ns puzzle
- Replies:
**40** - Views:
**5816**

Did you read the previous replies? My first solution for 9 involved the explicit use of Pi and skeptical scientist made the same observation that you did; in my second solution for 9 I use no explicit constants. In the previous reply, I was not giving a solution for 9, I was explaining to someone e...

- Thu Sep 13, 2007 10:00 pm UTC
- Forum: Mathematics
- Topic: Logarithms = ???
- Replies:
**21** - Views:
**3903**

- Thu Sep 13, 2007 5:18 am UTC
- Forum: Mathematics
- Topic: What to do - Adventure or finish school faster (or $?)
- Replies:
**4** - Views:
**1490**

### What to do - Adventure or finish school faster (or $?)

Need to decide pretty soon... If I go to grad school in 2008 I have to apply by the end of this year. I still have no idea which school I want to go to. I don't really know any math professors to give me recommendations (just transferred in this year), and I have to take the GREs. I have the general...

- Fri Sep 07, 2007 5:42 pm UTC
- Forum: Science
- Topic: Weird Science Teachers
- Replies:
**54** - Views:
**8256**

- Fri Sep 07, 2007 5:18 pm UTC
- Forum: Mathematics
- Topic: Group table
- Replies:
**6** - Views:
**1351**

- Fri Sep 07, 2007 5:05 pm UTC
- Forum: Mathematics
- Topic: My mathematical speed bump
- Replies:
**36** - Views:
**6364**

Nothing beats locking yourself in your room (preferrably on a saturday) and opening your book and working out all the problems until you figure it out. When you do figure something out and learn something new endorphins are released in your brain which provides motivation to learn more and work hard...

- Thu Sep 06, 2007 11:16 pm UTC
- Forum: Mathematics
- Topic: Peer-review my mathy blog post!
- Replies:
**23** - Views:
**3914**

### Re: Peer-review my mathy blog post!

Really it's the idea of a circle that the elements are trying to fit, not the circle itself, that makes a circle part of the universe. Perhaps you could say that they are always within epsilon of a true circle (using whichever method you like to determine how it's 'within')? It is like the skeleton...

- Thu Sep 06, 2007 8:20 pm UTC
- Forum: Mathematics
- Topic: Group table
- Replies:
**6** - Views:
**1351**

### Group table

I am learning about group tables. Let's take the additive group of integers mod 5. Here is the table. +_0 1 2 3 4 0_0 1 2 3 4 1_1 2 3 4 0 2_2 3 4 0 1 3_3 4 0 1 2 4_4 0 1 2 3 Using the table alone we can see what properties this structure has. It has closure, because only 0-4 appear in the body. It h...

- Thu Sep 06, 2007 4:18 pm UTC
- Forum: Mathematics
- Topic: Peer-review my mathy blog post!
- Replies:
**23** - Views:
**3914**

### Re: Peer-review my mathy blog post!

The real question you need to ask yourself, is there anything nature which is circle like at all? The circle is an abstract geometrical construct, really quite different in many respects to what the universe is made up off. Plenty of things look like circles. http://farm1.static.flickr.com/92/25181...

- Wed Sep 05, 2007 8:21 pm UTC
- Forum: Language/Linguistics
- Topic: Words you love.
- Replies:
**680** - Views:
**141749**

Holocaust It puts pictures of empty fading ghosts in your face (enhanced by the sound 'hollow'), then you have 'cost' at the end, but it's got a 'au' in it so you also think of 'caught', and the gh in caught along with the H at the beginning bring you back to 'ghosts'. Gauze? Say the word out loud ...

- Wed Sep 05, 2007 6:41 pm UTC
- Forum: Mathematics
- Topic: Peer-review my mathy blog post!
- Replies:
**23** - Views:
**3914**

- Tue Sep 04, 2007 3:40 pm UTC
- Forum: Mathematics
- Topic: Is 20 too old for a first real analysis course?
- Replies:
**32** - Views:
**7393**

- Fri Aug 31, 2007 9:02 pm UTC
- Forum: Mathematics
- Topic: Basic/Self-Evident Truth in Mathematics
- Replies:
**53** - Views:
**11994**

- Fri Aug 31, 2007 5:31 pm UTC
- Forum: Mathematics
- Topic: Basic/Self-Evident Truth in Mathematics
- Replies:
**53** - Views:
**11994**

- Fri Aug 31, 2007 5:18 pm UTC
- Forum: Mathematics
- Topic: Fractional Calculus (and other fun with diff. operators)
- Replies:
**20** - Views:
**3696**

- Thu Aug 30, 2007 11:07 pm UTC
- Forum: Mathematics
- Topic: Basic/Self-Evident Truth in Mathematics
- Replies:
**53** - Views:
**11994**

Why are you calling me a bot? I didn't know I had to post to any particular thread before I could participate in your forum. Some of the people here are just used to acting like weiners. In their defense, on the other hand, there is a rules thread (it's the first one) http://forums.xkcd.com/viewtop...

- Wed Aug 29, 2007 10:58 pm UTC
- Forum: Mathematics
- Topic: Inexact graph search algorithms
- Replies:
**15** - Views:
**3297**

- Wed Aug 29, 2007 6:53 pm UTC
- Forum: Mathematics
- Topic: Inexact graph search algorithms
- Replies:
**15** - Views:
**3297**

The more information you have about your function, the more efficient your algorithm can be. Without more information on the function, you need to at least search all of value 1s as has been said. The first question that needs answering is whether you can accept failures as long as they are unlikely...

- Tue Aug 28, 2007 10:51 pm UTC
- Forum: Mathematics
- Topic: Inexact graph search algorithms
- Replies:
**15** - Views:
**3297**

It seems to me that the goal in looking for an optimal algorithm would be not only to find the most accurate/quickest algorithm but to find the algorithm that is most probable to be most accurate/efficient. Without more information on your functions, no algorithm other than an exhaustive search of V...

- Fri Aug 24, 2007 4:53 pm UTC
- Forum: Mathematics
- Topic: I wonder know how interesting these formulas are
- Replies:
**7** - Views:
**2124**

- Wed Aug 22, 2007 11:33 pm UTC
- Forum: Mathematics
- Topic: "Chances Are... Adventures in Probability"
- Replies:
**1** - Views:
**1339**

- Mon Aug 20, 2007 7:24 pm UTC
- Forum: Mathematics
- Topic: What level of mathematics do people know on this forum?
- Replies:
**63** - Views:
**9622**

- Sun Aug 19, 2007 5:40 am UTC
- Forum: Mathematics
- Topic: Math Challenge - Irrational Numbers (make a proof)
- Replies:
**8** - Views:
**4453**

All fractions containing two integers do not repeat in decimal form eventually. pi/4 is a fraction. All rational numbers (I think this is what you meant) on the other hand do not repeat in decimal form eventually, unless you count 000000... as a repeating decimal (ie 3.2 = 3.200000000...), then in t...

- Thu Aug 16, 2007 5:57 am UTC
- Forum: Mathematics
- Topic: WLOG
- Replies:
**7** - Views:
**3089**

### WLOG

What does "without loss of generality" mean and when should it be used?

- Thu Aug 16, 2007 5:56 am UTC
- Forum: Mathematics
- Topic: Help with this theorem - accumulation pts and cpt sets
- Replies:
**11** - Views:
**2572**

No we didn't and later on he even taught us (in R) TFAE: 1) K closed and bounded 2) K compact 3) every infinite subset S of K has a limit point in K: S* intersect K is not empty This being specifically in R, I don't see why. I'd ask him but our next class is the final exam :( should have reviewed my...

- Thu Aug 16, 2007 5:15 am UTC
- Forum: Mathematics
- Topic: Help with this theorem - accumulation pts and cpt sets
- Replies:
**11** - Views:
**2572**

Not all compact spaces are closed. While it is true that a compact subspace of a hausdorff space is necessarily closed, it is not true that a compact subspace of an arbitrary topological space is closed. Take, for example, the indiscrete topology on R (the only open sets are the null set and all of...