# Calculus

- Elementary functions. Calculating limits, derivatives and integrals. Optimization problems
 Meta Thread / Thread Starter Last Post Replies Views Views: 2,637 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 46,290 I am using the PDF for log-normal distribution, which I'm referencing off the wikipedia page: here. I am integrating... Dec7-13 06:35 PM oneamp 2 572 http://i.imgur.com/rTf1iaC.png If instead of evaluating the above line integral in counter-clockwise direction, I... Dec7-13 08:33 AM vanhees71 7 892 I am trying to compute the determinant of the Jacobian matrix of the n-dimensional spherical coordinates. i will... Dec6-13 01:24 PM hedipaldi 0 539 Given a function f(x(t, s) y(t, s)), if is possible to compact \frac{∂f}{∂t}=\frac{∂f}{∂x}... Dec5-13 07:15 AM Jhenrique 5 694 Hello guys, I am quite unsure in how to start the modeling for population. If I define y as the number of infected... Dec5-13 01:40 AM elitewarr 4 644 I have run into some situations where I need to scale a number by an infinitesimal amount and would like to know the... Dec4-13 08:33 PM tanus5 10 699 Hi, I have been stuck on a problem for a while now (3.24 part c). My attempt is as follows: Internal virtual... Dec4-13 04:35 PM c0der 2 789 Let L be a forward operator and M be its adjoint defined using the inner product (f,Lg)=(Mf,g). Typically integration... Dec4-13 04:13 PM seanobeano 0 673 Assume we have a number ##S_0##. For ##i=1..n## defineS_i=\begin{cases}(1+b)S_{i-1}\text{ with probability... Dec4-13 03:59 PM mathman 1 492 If function is ##f(-x,-y)=f(x,y)##, is then ##\int^{a}_{-a}\int^{a}_{-a}f(x,y)dxdy=0##? Thanks for answer. Dec4-13 12:53 PM LagrangeEuler 6 622 My book loves to represent the delta function as: δ(r-r')=∫-∞∞exp(i(r-r')k)dk Now I can understand this formula... Dec4-13 05:42 AM pwsnafu 1 538 Hello! Exist a general formula to idea of lagrange multiplier, a compact formula that is possible to extract the... Dec3-13 01:45 PM Jhenrique 0 405 is there a closed form solution for this double integral? \int^{2}_{1}\int^{3}_{4}\sqrt{1+4x^{2}+4y^{2}}dydx Dec3-13 10:36 AM mabauti 5 829 Is it possible to formulate the second derivate trough of a tree diagram, as we do with a first derivative? If yes,... Dec3-13 06:06 AM Jhenrique 5 738 Hello there. I recently installed the Physics Forums app and could not find the homework section in the categories so... Dec2-13 06:33 PM Mark44 2 578 Hey guys. I am having some trouble visualizing one aspect of the Second derivative test in the 2 variable case... Dec2-13 04:03 AM Phoeniyx 8 734 In the process of calculating the integral \int_0^{2\pi}\frac{\sin{x} \cos{x}}{\sin{x}+\cos{x}}dx by contour... Dec2-13 04:01 AM jackmell 8 802 I know y is a function of x y=f\left(x\right)] with two known boundary conditions, that is f\left(x=A\right)=C and... Dec1-13 04:39 PM JulieK 3 558 If one uses Stokes' theorem and if two oriented surfaces S1 and S2 share a boundary ∂s then the flux integral of... Dec1-13 11:03 AM Gridvvk 0 473 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 7 596 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 4 614 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 2 640 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 1,283 In the context of my work (linear differential equations), it can not be zero. But why? Nov29-13 05:18 PM gikiian 8 698 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 5 746 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 4 559 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 3 571 * 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 1,006 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 7 547 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 2 853 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 4 801 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 1,303 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 5 614 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 2 529 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 1 652 Hello! What calculus textbook do you recommend for microbiology major or other biology majors? I heard good... Nov25-13 04:08 PM cpscdave 1 698 Hi, I've questions about the Fredholm integral equation : 1. Is an following eq. a(x)y(x) +... Nov25-13 03:28 PM mathman 4 595 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 1 460 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 1 601 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 1,363