# General Math

- Math topics not applicable to the categories below. High-school Math

### Math FAQ

Jul24-14 10:02 AM Greg Bernhardt

### Math Challenges

Test your skills. Math challenges will be posted at least once a week. Suggestions for problems are welcomed.
 Meta Thread / Thread Starter Last Post Replies Views Views: 2,591 Announcement: Follow us on social media and spread the word about PF! Jan16-12 Please post any and all homework or other textbook-style problems in one of the Homework & Coursework Questions... Feb23-13 09:23 AM micromass 1 39,006 I'm whacked outta solving these problems just hanging around for more than 2 hours for each question but can't solve... Jul7-09 07:05 PM slider142 9 1,068 Hey there, I was trying to check my calculations of one laplace tranformation and I needed to know a limit: f(x) =... Jan30-12 01:21 PM DemoniWaari 2 781 Hey guys, My cousin came over and was talking about his geometry class and it got me to derive 2*Pi*r and Pi*r^2... Apr3-09 06:30 PM MrJB 1 1,884 What free program (or online applet...) is there that I can use to numerically calculate limits and integrals... Mar18-08 11:35 AM daniel_i_l 0 1,231 Lim x->2^+ (1/x-1/2) Please help im having trouble taking this limit Apr6-05 07:55 PM dextercioby 19 6,893 I have worked out the limit as x tends towards +infinity for cos(1/x) to be 1, as cos (1/infinity) would be cos(0)... Dec5-09 05:20 PM grizz45 2 837 I was just wondering for the limit comparison test does it matter which function is on the top and bottom? Oct9-12 12:04 AM MarneMath 1 830 From first principles, \underset { x\rightarrow { 0 }^{ + } }{ lim } |x|=1\\ \underset { x\rightarrow { 0 }^{ - }... Nov1-12 01:57 PM tahayassen 4 724 Is there a limit to the number of different, regular n-gons comprising a uniform polyhedron? Mar22-08 02:08 AM Loren Booda 0 893 Is there a limit to the number of differing, regular n-gons that comprise a uniform polyhedron? Mar22-08 02:16 AM Loren Booda 0 1,021 Let A\subset X be a subset of some topological space. If x\in\overline{A}\backslash A, does there exist a sequence... Dec23-07 09:47 PM gel 13 2,094 hi , 1.)how do I find the limit of (x! e^x) / (x^x *x^1/2) as x tends to infinity ? 2.)and is f(x)= x! a... Jul30-05 11:13 AM TenaliRaman 8 1,180 how do you find the limit of this: ... Oct24-12 09:40 PM haruspex 5 2,463 I kind of know what limits are, or at least believe I do: I think that a limit of a sequence is just an... Aug25-14 06:50 PM Korisnik 6 344 I want to calculate the following: \displaystyle\lim_{k\to\infty}\frac{n_k}{d_k} where, n_0 = 2 Sep8-09 12:13 PM arildno 4 728 I was wondering someting that is so simple that it baffled me... When I have the equation a x^2+b x+c=0 this... Jul22-04 04:21 AM Galileo 5 7,133 I just wanted to know why the limit of arctanx as x approaches infinity is \frac{\pi}{2}. It doesn't make any sense to... Mar28-09 03:16 PM arildno 6 21,460 Hi The source coding theorem says that one needs at least N*H bits to encode a message of length N and entropy H.... Apr5-09 11:07 AM gop 4 937 Yesterday I thought of a math problem, and it seems very simple, as I assume the solution is, and I want to know the... Sep11-10 01:24 AM Hurkyl 1 778 Let f(x) and g(x) be functions. Then if limit of f(x)/g(x) = 1. That implies lim f(x) = lim g(x) right? ... May24-05 06:35 PM whozum 7 9,148 Hi, I don't know how to analyze the following, but I am wondering whether there is a way to determine whether a... Oct25-13 07:19 PM elementbrdr 6 721 What is the limit of this thx. Jul6-06 08:21 PM Robokapp 11 1,257 Can someone tell me how to show that the value of x/ approaches 1/r^2 when x approaches infinity? Cant figure... Dec28-05 05:48 PM Repetit 3 1,671 Hello. I have been trying to find this limit: Lim as x --> 1 of (sin((1-x)/2)*tan(Pi*x/2)) Of course I dont... Dec8-12 11:19 AM mfb 1 600 I have been reading through Schaum's and came across a limits question that i cannot figure out. I thought it had no... Jun12-07 03:10 AM eprjenkins 5 1,169 so i understand how to resolve a limit at x->oo, but from a conceptual standpoint, i do not get it. for example, ... Feb24-09 12:20 PM HallsofIvy 7 1,088 Hi, Consider a hypothetical. An investor short* sells Stock A for $100 and uses that money to buy Stock B for$100.... Jan20-11 05:55 AM AlephZero 10 1,524 I cant get the following limit to work: lim(X->0) 1/(ix)*(exp(imx) - 1 ) = m I'm sorry for the poor notation. I... Feb6-10 09:43 AM student111 2 2,165 In order that that other thread can get locked, here's something for JonF et al (sans organic detritus). Firstly,... Mar30-04 08:05 PM Hurkyl 24 2,342 Greetings. Let me first show how my teacher solves a limit. For example, take : Lim(x->6) (x+5)/(x-3) He takes the... Sep6-03 04:10 AM phoenixthoth 10 4,199 I have the following doubts. Please help me get through them..... (1) Is there any difference between the terms... Dec27-11 09:26 AM DivisionByZro 8 1,590 Thank you to those who replied to my previous post(I had a problem repling on that post). What I was after was a... Oct8-11 10:53 PM beartopper 0 850 1)We know this limit doesn't \lim_{x\rightarrow-\frac{2}{3}}\frac{2}{2+3x} exists after substituting the value ot... Jul9-09 06:19 AM tiny-tim 1 697 \lim_{x\rightarrowy}\frac{sin{x}-sin{y}}{x-y} so this is the question. I'm here solving this problem you please... Jul9-09 06:26 AM tiny-tim 4 808 I understand that the limit as x -> a for a polynomial function, f(x), is equal to f(a) because the function is always... Sep29-05 10:49 AM HallsofIvy 7 17,861 When sketching a graph I'm told to assume that the expression: f(x) =( e^x)/x Tends towards the infinite as x... Jan4-12 12:02 PM tomwilliam 2 754 I was told that the limit of e^-iwt as t-> infinity is 1 or is at least modelled as 1. Can anyone tell me why this is?... Oct22-11 05:01 PM schtruklyn 4 8,088 Hi everyone, I am having a 'crisis of faith' in how the limits of an integral should change when you make a... Jul9-13 09:45 AM BruceW 2 546 Hi, I'm having some trouble understanding what is meant when the limit of a summation is i