# Calculus

- Elementary functions. Calculating limits, derivatives and integrals. Optimization problems
 Meta Thread / Thread Starter Last Post Replies Views Views: 552 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 09:24 AM micromass 1 46,074 limn→∞(\frac{1}{n+1}+\frac{1}{n+2}+...+\frac{1}{4n}) Hi, when I first looked at this limit I thought that the... Nov30-13 06:48 PM lurflurf 7 586 It's easy to show that \frac{dy}{dx} of y = ln(ax) where a \in ℝ, a > 0 is always \frac{1}{x} : y = ln(ax) y =... Nov30-13 01:20 PM Mark44 4 604 I just recently discovered for myself this weird graph, can anyone explain to me what is exactly happening here. I... Nov29-13 07:28 PM lurflurf 2 634 I learned how to integrate it using the complex plane and semi circle contours but I was wondering if there is a way... Nov29-13 06:11 PM lurflurf 5 1,260 In the context of my work (linear differential equations), it can not be zero. But why? Nov29-13 05:18 PM gikiian 8 694 I would like to get an answer or pointers to suitable material, on the following question: I know that ∫|f(x)|2dx... Nov29-13 03:09 PM Simon Bridge 5 739 hello, i have a question about an explanation of integration as finding the area under a curve. I don't have any... Nov29-13 02:49 PM BOAS 4 554 In my high school Calculus course, I've encountered several optimization problems involving the area of a circle and I... Nov29-13 02:31 PM tiny-tim 3 560 * I know this is a very long post but it would mean the world to me if you could read it. I would really appreciate... Nov29-13 10:39 AM Office_Shredder 8 976 Hi, I have a basic question about convergence. I have two sequences, x1, x2, ... and y1, y2, ..., where yn =... Nov28-13 11:52 AM R136a1 7 543 Hey. There's one thing I've always been wondering about when it comes to deriving the expression for the moment of... Nov27-13 02:06 PM Nikitin 2 832 Dear Forum : I hung up with a integration http://ppt.cc/mIpV Can it be deduced to a simpler form? The... Nov27-13 01:49 PM Bill Simpson 4 795 Se a function f(x(t, s), y(t, s)) have as derivative with respect to t: \frac{df}{dt}=\frac{df}{dx}... Nov27-13 10:48 AM Jhenrique 25 1,288 I am completely self taught in Calculus, but I would like to have a better understanding of it before I go to College.... Nov27-13 02:41 AM SteamKing 5 608 While doing work, I always see notation like: F(x) = ∫0xf(t)dt - first equation F(x) = ∫1xf(t)dt What is the... Nov26-13 06:47 PM Office_Shredder 2 524 My tutor showed me something today, and I still can't completely wrap my head around why it makes sense. Consider the... Nov26-13 05:56 PM fzero 1 643 Hello! What calculus textbook do you recommend for microbiology major or other biology majors? I heard good... Nov25-13 04:08 PM cpscdave 1 681 Hi, I've questions about the Fredholm integral equation : 1. Is an following eq. a(x)y(x) +... Nov25-13 03:28 PM mathman 4 589 hey pf! so if i have a vector field \vec{V} and i know \nabla \cdot \vec{V}=0 would i be able to express \vec{V}... Nov25-13 09:51 AM pasmith 1 456 So \sqrt{306} is a pretty good approximation for Pi (=3.14155). If you add 1/51, so that you have \sqrt{306+1/51}... Nov25-13 03:09 AM CompuChip 1 598 Is there a proof that shows why indefinite integrals cannot be assessed when there are an infinite number of... Nov24-13 10:34 PM MathewsMD 19 1,342 For example, if you have the function f(x) = x2 then find: d/dx any number3x∫ t2dt Why must the dx in d/dx... Nov23-13 02:43 PM economicsnerd 5 614 Hi everyone! I have a question on functional derivatives. I have a function defined as:  F=\int d^3r \sum_{i=1}^3... Nov23-13 12:03 PM Einj 0 473 What is the integral of 1/(x^3 + bx - c) with respect to x? This is part of a larger problem I am working on, but... Nov23-13 08:37 AM yuiop 2 571 Hi all, Could someone please help me understand a small but significant step in the derivation of the wave equation... Nov23-13 05:39 AM rwilliams184 0 509 This is a forum where we chat about calculus problems that people are wondering about. I would greatly appreciate it... Nov22-13 11:02 PM CalculusManiac 3 806 How do I perform this integration: \int \left (\frac{dy}{dx}\right)^{2} dx Thanks! Nov22-13 12:37 PM SgrA* 11 940 Hi, take the function I(m,n) = Integral from 0 to 1 of sin(m*pi*x)*sin(n*pi*x) over dx depending from n and... Nov22-13 09:52 AM HallsofIvy 1 562 I have the following function f=\frac{B}{y^{3}}+\frac{C}{y^{4}}\mid\frac{dy}{dx}\mid where B and C are constants... Nov22-13 06:16 AM pasmith 1 481 I am trying to find the integral to this equation in order to obtain the cross section of a circle that has a radius =... Nov22-13 12:06 AM SteamKing 4 609 Given that D²f(x) = g(x), one form that eliminate the second derivate is integrating the equation: ∫∫D²f(x)dx² =... Nov21-13 12:38 PM Jhenrique 4 651 Hello all, I was curious on the practical applications of representing a sphere in four dimensions. I recently had to... Nov20-13 10:01 PM Myslius 4 904 how would describe the max/ min for the a constant function,eg. y =5 would you say all points are absolute and local... Nov19-13 08:03 PM SteamKing 1 542 If it's possible to relate the product rule with the binomial theorem, so: (x+y)^2=1x^2y^0+2x^1y^1+1x^0y^2... Nov19-13 11:49 AM HallsofIvy 3 719 Hi Could anyone give me a hint on getting a closed form for the following integral: \int\frac{1}{k + sin(x)}dx ... Nov18-13 08:26 PM darkfeffy 2 633 Hello all, I'm still a math newbie. I'm just about finished with part 1 of Spivak's calculus; this is my first... Nov17-13 09:40 PM HallsofIvy 18 2,307 I need help understanding why the ln (x) taylor polynomial is (x-1)-1/2(x-1)^2.... + etc. I cannot grasp the... Nov17-13 09:23 PM HallsofIvy 1 537 If exist differentiation until the nth order, so, why "no exist" integration until the nth order too? I never saw a... Nov17-13 08:21 PM Curious3141 5 889 I'm confused with limits of integrating and which to integrate first, I've been getting by so far with just knowing... Nov17-13 06:24 PM Mark44 7 755 Find a number "k" such that exist only one intersection between the curve exponential k^x e and the straight x·k. This... Nov17-13 05:54 PM PSarkar 5 552