## Search found 22 matches

Sat Dec 24, 2011 4:00 pm UTC
Forum: Mathematics
Topic: Multiple Choice Problem
Replies: 9
Views: 1926

### Re: Multiple Choice Problem

Wow whose bumping all those old threads !!!
Fri Dec 23, 2011 5:27 pm UTC
Forum: Mathematics
Topic: Math Books
Replies: 378
Views: 260170

### Re: Math Books

Hi everybody. I was wondering if someone had a good suggestion for a book on advanced number theory . Also I'm looking for a good book on intuitionism. I've tried Intuitionism , An Introduction by Heyting but I hate the Galileo " Discourses and Mathematical Demonstrations Relating to Two New Sc...
Wed Dec 21, 2011 6:10 pm UTC
Forum: Mathematics
Topic: Odd factors of 2^n-1?
Replies: 5
Views: 2142

### Re: Odd factors of 2^n-1?

It's pretty hard without modular arithmetic ... but once you know Euler's theorem and Euler's totient function the proof becomes pretty trivial ( 2 is always coprime to odd numbers so if n is an odd number : 2^{\phi(n)} \equiv 1 \ (mod \ n) which means that 2^{\phi(n)} - 1 is...
Thu Dec 08, 2011 8:26 pm UTC
Forum: Mathematics
Topic: Convergence Tests For Series
Replies: 29
Views: 5989

### Convergence Tests For Series

Hi everybody. I was just wondering if there is a theorem or logical reasoning why convergence tests for series will always be inconclusive for certain series ... Thanks for your help.
Thu Dec 01, 2011 4:46 pm UTC
Forum: Mathematics
Topic: Requesting Inequalities and Tips to Solving Them
Replies: 9
Views: 2276

### Re: Requesting Inequalities and Tips to Solving Them

If you want some really advanced notions of inequalities, I advise you to read "Handbook of Means and Their Inequalities" by Bullen. It's a bit bulky but very informative ...
Thu Dec 01, 2011 3:17 pm UTC
Forum: Mathematics
Topic: can you crack it?
Replies: 13
Views: 8187

### Re: can you crack it?

I thought it was an Ascii art or some phonetic lingo rather than a real cryptographic problem ... I tried ascii arting it and got something like an S or a 5 or an inverted Z but the other half was bullsh*t though ... so maybe it's just a crypto then
Fri Nov 18, 2011 3:23 pm UTC
Forum: Science
Topic: Well, this could change things (neutrinos)
Replies: 289
Views: 42268

### Re: Well, this could change things (neutrinos)

Hmmm I have a noob question: How do they measure the time of departure and time of arrival of these neutrinos ???
Sat Nov 12, 2011 1:27 pm UTC
Forum: Logic Puzzles
Replies: 217
Views: 64484

### Re: The surprise exam paradox

Still don't understand why this isn't classed simply as an inconsistent theory.
Fri Sep 23, 2011 8:05 am UTC
Forum: Science
Topic: Well, this could change things (neutrinos)
Replies: 289
Views: 42268

### Re: Well, this could change things

Thought it was from a school lab, but if it's from the CERN then there's a high chance it could be true. But I really hope that they made a mistake cos it could bring down 100 years of physics ....
Sat Sep 17, 2011 7:11 pm UTC
Forum: Mathematics
Topic: Proof By Induction
Replies: 13
Views: 1929

### Re: Proof By Induction

Thanks everybody for your posts and helping me clear this doubt. But I still think that I'll avoid using induction because I could be sacrificing real mathematical understanding for convenience. :D By the way the book was Discrete Mathematics by Rosen and the quote :"It is extremely important t...
Thu Sep 15, 2011 6:27 pm UTC
Forum: Mathematics
Topic: Proof By Induction
Replies: 13
Views: 1929

### Proof By Induction

Hi everybody. I've been reading a few books about mathematical reasoning and I came across an interesting statement in one of the books but I can't remember which one, which said something like "induction can only be used to prove a result obtained some other way but can't be used to discover n...
Mon May 30, 2011 5:00 pm UTC
Forum: Mathematics
Topic: alternative mathematics
Replies: 128
Views: 14042

### Re: alternative mathematics

kumarevo wrote:The existing angles of 180 degrees, if you specify items may be quadrilateral, pentagon...

task. prove ,to be a real number , result of division of two integers (a fraction)

With the commas it's clearer.
This is becoming more linguist and hieroglyphical than a mathematical
Wed May 25, 2011 2:01 pm UTC
Forum: Mathematics
Topic: Cutting a polygon into triangles (Polygon triangulation)
Replies: 2
Views: 1882

### Re: Cutting a polygon into triangles (Polygon triangulation

Is it what you meant Tirian? 2.png Let N n be the number of ways of triangularising a n-polygon. If I fix a side and draw a triangle to any vertex ( excluding the fixed side) , I always get two polygons on the left and on the right of my triangle whose sum of sides= n+1. Because the number of ways o...
Wed May 25, 2011 10:12 am UTC
Forum: Mathematics
Topic: Cutting a polygon into triangles (Polygon triangulation)
Replies: 2
Views: 1882

### Cutting a polygon into triangles (Polygon triangulation)

I was reading about Catalan numbers in a book and it said that the number of ways of cutting a n side convex polygon into triangles is the n-2 th Catalan number e.g for a pentagon there's 5 ways and for a hexagon there's 14 ways. http://upload.wikimedia.org/wikipedia/commons/3/36/Catalan_number_poly...
Sun May 22, 2011 12:33 pm UTC
Forum: Mathematics
Topic: alternative mathematics
Replies: 128
Views: 14042

### Re: alternative mathematics

Natural axiom: Natural along. Point is the beginning (end) longer natural. Natural along with 2 points. Natural along the base length. Natural longer connecting points. There is always the first point (A). MS.A-Natural along . Point . What does Natural along mean? Give us a clear and simple example...
Thu May 19, 2011 8:50 am UTC
Forum: Mathematics
Topic: Solving PDE's
Replies: 9
Views: 1545

### Re: Solving PDE's

Ok last question. If y = x− ct and z = x+ct and u(x,t)=v(y(x,t),z(x,t)) then using the Chain rule is the following eqn correct ?: \frac{\delta u}{\delta t}= \frac{\delta v}{\delta y}\frac{\delta y}{\delta t}+ \frac{\delta v}{\delta z}\frac{\delta z}{\delta t} And also I'm not too sure how to apply ...
Wed May 18, 2011 5:31 pm UTC
Forum: Mathematics
Topic: Solving PDE's
Replies: 9
Views: 1545

### Re: Solving PDE's

Ok last question. If y = x− ct and z = x+ct and u(x,t)=v(y(x,t),z(x,t)) then using the Chain rule is the following eqn correct ?: \frac{\partial u}{\partial t}= \frac{\partial v}{\partial y}\frac{\partial y}{\partial t}+ \frac{\partial v}{\partial z}\frac{\partial z}{\partial t} And also I'm not too...
Tue May 17, 2011 8:23 pm UTC
Forum: Mathematics
Topic: Solving PDE's
Replies: 9
Views: 1545

### Solving PDE's

Hi everybody. Just wondering if someone can help me out on some simple PDE's. Btw I'm just a math student and we're supposed to know how to solve some easy PDE's this semester but all the tutorials I've come across on the internet contain a lot of Physics and Engineering jargon. So I have to solve t...
Mon May 02, 2011 12:24 pm UTC
Forum: Mathematics
Replies: 8
Views: 1932

I did 3 by a long and rigourous method , by breaking up the digits into sequences For 7: 7\times10^{2n+2} , n\geq0 , where n represents the nth term For 1's: (\sum_{i=0}^{n}10^{n+1+i}) - 10^{n+1} = 10^{n+1}(\frac{10^{n+1}-10}{9}) For 2: 2\times10^{n+1} For 8's: (8\sum_{i=0}^{n}10...
Fri Apr 22, 2011 10:32 am UTC
Forum: Mathematics
Topic: Tarski's World
Replies: 3
Views: 1645

### Re: Tarski's World

Thanks a lot. Now it seems to make sense !!!
Tue Apr 19, 2011 8:19 am UTC
Forum: Mathematics
Topic: Tarski's World
Replies: 3
Views: 1645

### Tarski's World

Hi everybody. I'll be doing FOL next year so I'm reading a book on Tarski's World but I don't have the software. So if someone could please give me a brief description of what "Tarski's World" is all about and how it works , I'll be grateful
Mon Apr 04, 2011 12:43 pm UTC
Forum: Logic Puzzles