# 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: 4,781 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 39,224 I want to map the temperature gradient in my part of town. I live within spitting distance of the lake and want to... Sep10-07 04:47 PM DaveC426913 9 2,252 Hey, does anyone knwo of a program that can train you in different basic fields of mathematics, and preferrably keep... Sep10-07 03:29 PM menager31 9 6,019 What is SUBSET on “open subset of R^{n}"? How supposed I imagine the following equations? u : U → R Sep10-07 01:08 PM JonF 1 1,235 A gift shop sells pewter mugs for $35. They are currenly running an engraving promotion. The first six letter are... Sep10-07 06:33 AM JonF 11 4,846 Why the mathematician call identification topology "quotient topology"?from my viewpoint,identification topology bear... Sep10-07 06:29 AM navigator 3 1,450 (1) using stokes theorem and cutting the surface into 2 parts how can we prove that \int curl A.n dS = 0 ... Sep10-07 06:25 AM mathwonk 22 5,336 how could i expand something such as arctan'x into a power series. also how would you be able to find the power series... Sep10-07 05:41 AM HallsofIvy 7 28,185 I've been really stumped by this one from my math class. It's a two variable trig. question with two equations. I... Sep9-07 04:30 PM rocomath 7 1,448 I have tried this question (http://img524.imageshack.us/img524/9539/scan0001pa1.png) a number of times and always use... Sep9-07 07:32 AM HallsofIvy 10 2,268 hi can anyone tell me how could one go about to prove x* (delta)' ~ -delta where delta is the dirac delta... Sep8-07 02:33 PM Hurkyl 11 1,326 General Info. A Mathematician's Apology is a 1940 essay by British mathematician G. H. Hardy. It concerns the... Sep8-07 07:05 AM AlephZero 3 2,787 I'm looking for a particular (actually, there are probably several) of two numbers that are "extremely close... Sep8-07 06:13 AM Gib Z 13 1,838 Dear all valuable experts, I'm looking for a free based maths graph plotting software which could display a sketch... Sep8-07 02:14 AM rela 3 1,304 for example...is there some software that will let me do all my calculations mod 2 or something? free software would... Sep7-07 06:25 PM matt grime 3 1,185 There are SIN and SINH. The first one is familiar as SINUS on calculus (or trigonometry), but, I don’t know what SINH... Sep7-07 02:16 PM HallsofIvy 6 15,794 hey i know the basics about complex numbers like: 5*i^7 = 5*i^3 = 5 * -i = -5i = (- pi/2, 5) but now : how... Sep7-07 02:09 PM HallsofIvy 10 1,896 This is for a PnP RPG I am creating... I've looked around for places on the internet, but haven't really found... Sep7-07 10:22 AM CRGreathouse 18 2,488 hello commonly we have: \int^t_0 \ dx=M "M" is a specific number (the result of integal) my question: having... Sep7-07 06:18 AM HallsofIvy 4 2,308 I've found a new way for finding the circumference of a circle by using a visual perspective ,an angle of 18 degrees,... Sep6-07 05:43 PM phi-lin good 3 5,099 Ok so the problem: 2 trains are 100 miles apart traveling towards each other on the same track. Each train tavels... Sep6-07 01:50 PM JonF 8 9,159 I think I have returned all my math back to teachers without any refund. y=f(x); h=xb-xa, which is very small. ... Sep6-07 01:48 PM JonF 5 7,975 For the most recent post in PF, which is most likely: few or no replies, or many replies? Is there a distribution of... Sep6-07 08:09 AM cristo 2 1,271 Hello friends. If anybody of you are interested in my theory of planar angles and trimetry, you can see de enclosed... Sep6-07 06:45 AM ferman 0 1,594 Does anyone can solve the following equation x^2 – x < 0 Here is the solutions of mine: x^2 – x < 0 x(x – 1)... Sep6-07 06:43 AM HallsofIvy 2 1,373 I need samples of parametric equations: x=Fx(t); y=Fy(t); the samples must be useful or famous in math, physics... Sep6-07 04:36 AM xyz3003 2 1,360 I currently attend a community college. For several semesters I did poorly--failed one class and dropped out of a... Sep5-07 11:06 PM mathwonk 6 6,104 I am confused myself, so I post the Q. when we talk about "definite integral of area" in rectangular or polar... Sep5-07 09:35 PM xyz3003 0 2,893 Hello, was wondering if someone could help me with a little vector maths problem please. What I need to find is the... Sep5-07 07:18 PM ice109 3 2,750 Hi again everyone… I have 3 questions: 1) What is the difference between INVERSE and RECIPROCAL? 2) Does... Sep5-07 11:48 AM HallsofIvy 2 1,177 n = (28)^3 which is greater: the units digit of n OR 4? Sep5-07 10:05 AM uart 15 2,652 Disregard this, Sorry i posted a hw question by accident. Sep4-07 08:02 PM Lemm 0 1,297 I've been reading some books on theoretical physics lately, namely stuff by Michio Kaku. I am heading to college in... Sep4-07 05:33 PM Dragonfall 3 1,416 So I decided to buy the book The Elements because i couldn't pass the offer up(for$10, can you believe that?) and... Sep3-07 03:17 PM mathwonk 4 2,361 i dont understand the point of \hat{\theta} if a vector is completely described by \textbf{r}=r \hat{\textbf{r}} ... Sep3-07 12:56 PM ice109 4 4,142 Hello friends, I am studying in 10th class. Actually I have a question and I’m unable to solve this question. My... Sep3-07 12:31 PM ryan_276 3 1,033 I wanted to know , if x(n) has DTFT X(e^jw) then can we define Y(e^jw) in terms of X(e^jw)? where Y(e^jw)is DTFT... Sep3-07 03:43 AM ratn_kumbh 1 1,489 I understand that infinity - X = infinity. However, what I don't understand is this. If I have: infinity - 1 =... Sep2-07 10:07 PM Hurkyl 4 4,823 Another vent of frustration: I hereby nominate the three worst offences committed in maths textbooks as 0.... Sep2-07 08:31 PM PowerIso 38 5,011 Hello everyone, I use a TI-83 Plus and I'd like to know if there is a quick way to convert an angle from radian to... Sep2-07 06:10 AM HallsofIvy 5 38,725 norm is defined to be the length of the vector and we put we denote it by ||a||. However, modulus |a| also means... Aug31-07 11:19 AM Chris Hillman 6 5,223