Search found 150 matches

Mon Apr 01, 2013 7:55 pm UTC
Topic: 1193: Externalities
Replies: 505
Views: 142471

Re: 1193: Externalities

I have pyskein 0.7.1 and am matching what the website gives except for in the one case where I tried using some curse words and numbers mixed together
Wed Jan 13, 2010 2:53 am UTC
Forum: Mathematics
Topic: Is there a such thing as a cardinality under aleph null?
Replies: 18
Views: 1762

Re: Is there a such thing as a cardinality under aleph null?

If a set is infinite, you can remove any finite number of objects and it maintains being infinite. In particular you can remove one object, then another object, then another object, etc. So you can map aleph 0 into your infinite set (by counting the objects you removed) and hence aleph 0 must be at ...
Thu Jan 07, 2010 1:58 pm UTC
Forum: Mathematics
Topic: Group theory: do some sets have implied operations?
Replies: 10
Views: 1549

Re: Group theory: do some sets have implied operations?

R* is used to denote the ring of units but someone taking group theory for the first time may not have seen that notation. As an example of how obvious the group operation in question is let's take a look at Z 2 . I claim there are two possible groups 1) The operations addition operation as we know ...
Sat Dec 05, 2009 7:35 pm UTC
Forum: Mathematics
Topic: Number of paths under diagonal
Replies: 10
Views: 1315

Re: Number of paths under diagonal

Fri Jun 12, 2009 11:32 am UTC
Topic: 0596: "Latitude"
Replies: 84
Views: 21845

Re: "Latitude" Discussion

Hmm... I thought Megan bought a sexbot and installed an arc welder on it
Fri Jun 05, 2009 3:20 pm UTC
Forum: Mathematics
Topic: Real-world examples of -x * -y = +z
Replies: 66
Views: 7480

Re: Real-world examples of -x * -y = +z

Sure it is. All you have to do is interpret the two numbers differently: one is a point on the number line, and one is a scale factor. Negative scale factors are "orientation-reversing." Yes, you have positive times positive is positive because three groups of four apples is twelve apples...
Fri Jun 05, 2009 7:08 am UTC
Forum: Mathematics
Topic: Most frequently occuring digit
Replies: 17
Views: 1747

Re: Most frequently occuring digit

Does 1x10^10 have two zeroes or ten zeroes?
Mon Jun 01, 2009 5:12 am UTC
Topic: 0591: "Troll Slayer"
Replies: 178
Views: 182814

Re: "Troll Slayer" Discussion

This comic was awesome. Then I read the alt-text. Genius!

And good call pyro
Tue Apr 28, 2009 5:47 am UTC
Forum: Mathematics
Topic: Good problem for a 10th grader?
Replies: 32
Views: 2683

Re: Good problem for a 10th grader?

Lol, you're right quintopia. I normally don't write it that way, so when I saw your quote I thought you were bolding my text

Mon Apr 27, 2009 11:22 pm UTC
Forum: Mathematics
Topic: Good problem for a 10th grader?
Replies: 32
Views: 2683

Re: Good problem for a 10th grader?

3,5,7 is not the only set of consecutive primes all of which are odd. In fact, all but one set of three consecutive primes are all odd. I thought that you'd say that, but I don't see how you can interpret it that way from the sentence structure. I avoided saying three consecutive odd primes for a r...
Mon Apr 27, 2009 10:49 pm UTC
Forum: Mathematics
Topic: Good problem for a 10th grader?
Replies: 32
Views: 2683

Re: Good problem for a 10th grader?

quintopia, what's the other interpretation?
Mon Apr 27, 2009 7:13 pm UTC
Forum: Mathematics
Topic: Good problem for a 10th grader?
Replies: 32
Views: 2683

Re: Good problem for a 10th grader?

The solution is incredibly easy to understand, so even if the problem is too hard it's simple to just ask the question, have her struggle over it, then give the solution. Then use this as a jumping off point to other similar questions. If the question's too easy, that's fine, because you can use it ...
Sun Apr 26, 2009 2:39 am UTC
Forum: Mathematics
Topic: question that I have no Idea how to go about
Replies: 10
Views: 1123

Re: question that I have no Idea how to go about

It's obvious that if the die is not a 2 or a 1 you re-roll it. If you get a 2 on your first die, my gut instinct is that it's better to re-roll, because you have lots of chances to get a 2 again, and are fairly unlikely to get straight 1's on your other dice.
Sun Apr 26, 2009 2:26 am UTC
Forum: Forum Games
Topic: Name a smaller (closer to zero) number.
Replies: 52
Views: 4400

Re: Name a smaller (closer to zero) number.

Previous number divided by -2
Sat Apr 25, 2009 10:48 pm UTC
Forum: Mathematics
Topic: My question might annoy those who know the answer
Replies: 13
Views: 1309

Re: My question might annoy those who know the answer

I'll try again

∅rly?
Sat Apr 25, 2009 6:24 pm UTC
Forum: Mathematics
Topic: Math: Fleeting Thoughts
Replies: 408
Views: 130821

Re: Math: Fleeting Thoughts

Did you divide by the volume of an M&M?\

You might want to find the height and diameter and assume it's a box shape instead because they don't fit together perfectly
Fri Apr 24, 2009 5:30 am UTC
Topic: 0573: "Parental Trolling"
Replies: 78
Views: 18852

Re: "Parental Trolling" Discussion

BlueEyedGreen wrote:I love how everything in the future is curvy, and how computers are just sleek glowing membranes floating at desk level.

I didn't even notice that
Fri Apr 24, 2009 5:19 am UTC
Topic: 0573: "Parental Trolling"
Replies: 78
Views: 18852

Re: "Parental Trolling" Discussion

Let's be honest, this comic would only be mildly amusing except for the use of 'bleegle warble yargle' for when she can't speak
Fri Mar 27, 2009 8:39 pm UTC
Forum: Mathematics
Topic: Here's a fun problem...
Replies: 27
Views: 3216

Re: Here's a fun problem...

A sucker would expect a heads to increase the chance of a tails coming up next. Most people aren't suckers, so will pick heads to come up next. He knows most people aren't suckers, so the coin's rigged to come up tails. More seriously, itaibin, I can't believe that him flipping the coin and it landi...
Mon Mar 23, 2009 7:50 pm UTC
Forum: Mathematics
Topic: Alternative definitions of the derivative
Replies: 15
Views: 2020

Re: Alternative definitions of the derivative

I should be using math fonts but I forget the syntax. If f : R^n -> R^m is differentiable at a E R^n. There exists a linear transformation L : R^n -> R^m such that lim h-> 0 |(f(a + h) - f(a) - L(h))|/|h| = 0 The function L is refered to as the derivative of f at a. real-valued single-variable func...
Sun Mar 22, 2009 1:47 pm UTC
Forum: Mathematics
Topic: Uncountably many vertical asymptotes?
Replies: 18
Views: 2000

Re: Uncountably many vertical asymptotes?

Something that sort of fits what you're looking for: f(x) = 0 if x is irrational and if x is rational, say x = m/n, then f(x) = n f is locally unbounded everywhere. You don't get the limit of f approaching infinity as x approaches a point (since it doesn't exist) but the limsup does for every point....
Thu Mar 19, 2009 6:32 pm UTC
Forum: Mathematics
Topic: Different definitions of an open set
Replies: 18
Views: 1522

Re: Different definitions of an open set

Define T to be the closure of T' under finite intersection and countable union. Then T happens to match all of the requirements of a topology on S.

You need uncountable unions also
Thu Mar 12, 2009 11:49 pm UTC
Forum: Mathematics
Topic: Math problem help
Replies: 9
Views: 891

Re: Math problem help

You should have a formula describing distance as a function of time and acceleration which you can solve
Tue Mar 10, 2009 2:14 pm UTC
Forum: Mathematics
Topic: Graph: F(x)=x^∞
Replies: 25
Views: 2927

Re: Graph: F(x)=x^∞

For a quick answer: \lim_{x\to\infty}\frac{1}{x^2}=\frac{1}{\infty^2} = \frac{1}{\infty} = 0 \lim_{x\to\frac{\pi}{2}}\frac{1}{cos(x)}=\frac{1}{cos(\frac{\pi}{2})} = \frac{1}{0} = \infty Meaning, in the context of limits at least (an underlying basis of many other things like derivat...
Mon Mar 09, 2009 1:24 pm UTC
Forum: Mathematics
Topic: Find if a number has a root
Replies: 8
Views: 1099

Re: Find if a number has a root

There are all kinds of algorithms. A not very efficient one is: Given a number y for which we are trying to find positive integer roots, we will find them only if y is a positive integer. Write the equation x^n=y. This is the same as finding roots for x^n-y=0. If there is an integer root k, (x-k) i...
Sun Feb 08, 2009 2:33 am UTC
Forum: Mathematics
Topic: The probability of impossible
Replies: 63
Views: 6884

Re: The probability of impossible

It should be noted that as long as your sample space is countable, that p(x)=0 does in fact imply that x is impossible. It's only when you have uncountable sample spaces, like the set of real numbers or the set of infinite sequences H or T that you start getting into these problems (if problem is th...
Mon Nov 24, 2008 3:12 pm UTC
Forum: Logic Puzzles
Topic: Right and Left - Truth and Lies.
Replies: 23
Views: 3279

Re: Right and Left - Truth and Lies.

Holy cow! What if they're ambidextrous!
Fri Nov 21, 2008 5:38 pm UTC
Forum: Mathematics
Topic: Favorite math jokes
Replies: 1452
Views: 470856

Re: Favorite math jokes

Why did the vector cross the road? He wanted to be normal A baseball coach once had the most talented team he'd ever seen. Unfortunately, it all got flipped upside down when he put his naturals in a field. An infinite number of mathematicians walk into a bar. The first one orders a beer. The second ...
Fri Nov 21, 2008 5:14 pm UTC
Forum: Mathematics
Topic: Analysis success suggestions?
Replies: 3
Views: 741

Re: Analysis success suggestions?

Become more than familiar with definitions, what they mean, and alternative formulations. Continuity is a good example, you have the standard epsilon-delta definition of a continuous function, but you also have a function is continuous if and only if for all convergent sequences (x k ) (converging t...
Fri Nov 14, 2008 5:32 pm UTC
Forum: Mathematics
Topic: Which is bigger?
Replies: 35
Views: 3213

Re: Which is bigger?

Maybe you shouldn't have bought them so much food
Thu Nov 13, 2008 10:39 pm UTC
Forum: Mathematics
Topic: Which is bigger?
Replies: 35
Views: 3213

Re: Which is bigger?

Even larger than 3->3->65->3?
Thu Nov 13, 2008 7:42 pm UTC
Forum: Mathematics
Topic: Minimum bit string (shortest common superstrings)
Replies: 20
Views: 2157

Re: Minimum bit string

If you start with the string of n 1's, then you add a 0, you get the string with a 0 at the end... adding on more 1's gives you each string with a single 0 placed somewhere inside the string. You can't extend this exactly for two zeros as far as I can tell, but that's a bit more of a systematic star...
Thu Nov 13, 2008 5:54 pm UTC
Forum: Mathematics
Topic: Adding Repeating Decimals (not *quite* .999...=1)
Replies: 28
Views: 2752

Re: Adding Repeating Decimals (not *quite* .999...=1)

If I have a distinct .000....1 and I multiply it by 10, what do I get? This is the biggest problem with trying to use an intuitive decimal notation for a 'super small' number
Thu Nov 13, 2008 12:29 pm UTC
Forum: Logic Puzzles
Topic: Equilibrium Strategy for "Tension"
Replies: 14
Views: 1798

Re: Equilibrium Strategy for "Tension"

If the number of bins is less than the number of people,
Spoiler:
then n people each putting all their chips into a different of the bins gives an equilibrium (the rest of the players don't bid at all). It's not a very interesting one though
Wed Nov 12, 2008 9:24 pm UTC
Forum: Mathematics
Topic: Direct proof of compactness
Replies: 18
Views: 1651

Re: Direct proof of compactness

Proving the Heine Borel theorem and then using the Heine Borel theorem is still using the Heine Borel theorem.
Wed Nov 12, 2008 6:33 pm UTC
Forum: Mathematics
Topic: Direct proof of compactness
Replies: 18
Views: 1651

Re: Direct proof of compactness

"Unroll" the definition of the Heine-Borel theorem and apply it. If whatever grading authority says that's still using the Heine-Borel theorem, add a line in the unrolled definition stating "For all b in B, the set of bananas, b is a banana". Because the Heine-Borel theorem neve...
Wed Nov 12, 2008 3:04 pm UTC
Topic: 0503: "Terminology"
Replies: 292
Views: 44418

Re: Terminology

Re: Africa. Let's be honest. Rome beat Carthage, the Persians took Egypt, and it was pretty much game over for the whole continent. It's kind of like getting zerg-rushed

I think we should refer to Antarctica as the deep south from now on
Mon Nov 10, 2008 10:40 pm UTC
Forum: Mathematics
Topic: Direct proof of compactness
Replies: 18
Views: 1651

Re: Direct proof of compactness

If there's an open cover of K, it must be 0 is contained in one of the covering sets. What else does that covering set cover (hint: A lot of other points)
Thu Nov 06, 2008 7:12 pm UTC
Forum: Mathematics
Topic: How do you prove that a function is continuous?
Replies: 12
Views: 7483

Re: How do you prove that a function is continuous?

And yet you're the only person who didn't understand what level of math answers should be at. Someone working with rings of continuous functions over a compact space does not need to know how to prove sinx + 2 is continuous
Wed Nov 05, 2008 11:33 pm UTC
Forum: Forum Games
Topic: Word Chain II
Replies: 51
Views: 4135

Re: Word Chain II

tricky77puzzle wrote:
Office_Shredder wrote:freed to slave

Spoiler:
freed
feed
fed
lave
slave

He asked for slave to free, not freed.

Oh, whatever. Just change it to

free
freed
repeat

That was trivially fixable without comment I think