Calculus

- Elementary functions. Calculating limits, derivatives and integrals. Optimization problems
 Meta Thread / Thread Starter Last Post Replies Views Views: 5,739 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 46,611 hi there, just new to this form Nov12-09 04:25 PM mathman 4 1,156 Hi, I need two simple proofs of complex inequalities. 1) |1-z|/|z|<2 2)|1+z|/|z|>1/2 Ik need them for a... Nov12-09 03:03 PM Belgium 12 2 737 so I have a semi circle that goes from \frac{5\pi}{4} to \frac{\pi}{4} so the angle between the x axis the... Nov12-09 09:37 AM LumenPlacidum 1 1,858 I need to find the vertical sections and level curves of the function z=max(x,y^2) associated with the constant... Nov12-09 08:55 AM LumenPlacidum 1 2,009 Hello! I wanted to solve this integral but really didn't understand the method show in the book. Can anyone help me... Nov11-09 03:37 PM kranav 2 902 Let b be a real number. Correct me if I'm wrong, but it seems that: (1) The interval (b,b) is empty, as are the... Nov11-09 03:30 PM Hurkyl 1 594 What is the algebra required to rewrite the nth term of: (sum from n=0 to infinity) of (pi^n)/(3^n+1) in geometric... Nov11-09 03:16 PM ollybabar 2 2,107 Hi all, In proof of derivative of lnx, \frac{d}{dx}(lnx)=\lim_{\Delta x\rightarrow 0}\frac{\ln(x+\Delta x)-lnx... Nov11-09 01:01 PM l'Hôpital 1 2,957 given the set of moments m_k obtained from the known measure w(x) \int _{-\infty}^{\infty}dx w(x) x^{k} = m_k ... Nov11-09 12:31 PM zetafunction 0 617 Recently, I proved that Given f:A \rightarrow \mathbb R is uniformly continuous and (x_{n}) \subseteq A is a Cauchy... Nov10-09 04:45 PM snipez90 3 984 define F(x)=x, then uF is the lebesgue stiljes measure duF=dx Let y=x^2 we all know that how to transform \int... Nov10-09 06:58 AM emamm 4 2,054 The energy of a magnetic dipole in an external magnetic field is U = - \mathbf{m} \cdot \mathbf{B} Yet if I try to... Nov9-09 04:16 PM fantispug 8 5,572 I always have trouble sketching regions and solids. For example, if one solid described by the inequialities (in... Nov9-09 12:44 PM LCKurtz 2 1,726 If two spheres of radius 1 intersect each other so the surface of each sphere passes through the other’s center how... Nov9-09 11:44 AM volleyball21 2 1,286 Hey: How to get the green function for laplace equation with dirichlet on the boundary for a CUBE domain? I've... Nov9-09 10:48 AM Kaiser.LIU 0 3,064 How would I calcluate a surface integral in dimensions greater than 3. For example, from the definition of a... Nov9-09 09:49 AM Hurkyl 1 806 Hello, The general solution of a differential equation for y'+P(x)y=G(x) is y(x)=e^{-\int P(x)dx} for y'+xy=x... Nov8-09 12:07 PM coki2000 2 2,832 I'm trying to express the polar rose as an implicit function: r(t)=sin t x = sin t * cos t y = sin^2 t Since... Nov8-09 06:44 AM tiny-tim 10 1,587 Hello! Can you tell me the sufficient condition for the existence of the vector potential? Thank you very much! Nov7-09 07:19 PM ManuelF 4 1,126 As mentioned in the title~ Could anyone give me a hint or an idea ? Thanks~ Nov7-09 10:17 AM abcdefg10645 2 3,103 I'm not completely familiar with measures yet, but am trying to be. I'm trying to show a that a few sets in Rn have... Nov7-09 09:36 AM rochfor1 6 3,701 given a function f(x) with a truncated Taylor series f(x)= a_{0}-a_{1}x+ a_{2}x^{2}-a_{3}x^{3 }- ... even in... Nov7-09 05:48 AM zetafunction 0 1,853 I'm trying to show that a function f(z) is analytic by showing f'(z) exists. But f(z) is defined in terms of a contour... Nov6-09 07:18 AM Phyisab**** 2 1,857 Could someone explain this to me please where n=y/squareroot(4vt) ∂C/∂t=(dC/dn)(∂n/∂t)=-(1/2)(n/t)(dC/dn) When i... Nov5-09 08:48 PM juice34 2 646 My textbook notes that if: \frac{x^{2}}{a^{2}}+ \frac{y^{2}}{b^{2}} + \frac{z^{2}}{c^{2}}=1 and a \neq b \neq c... Nov5-09 07:55 PM IniquiTrance 2 736 I honestly enjoyed using James Stewart (yes heathen) when I did calc I, II, III and now these forums are buzzing with... Nov5-09 04:52 PM heldervelez 5 2,930 I am trying to measure a concrete structure to compute the surface area. I have included a sketch of the structure... Nov5-09 12:21 PM jonlorio 1 1,367 Hello - I have a problem in general finding the region in which the Laurent series converges... Could someone... Nov5-09 03:49 AM Butelle 4 966 the idea is , do orthogonal polynomials p_{n} (x) have always REAl zeros ? for example n=2 there is a second... Nov5-09 03:46 AM HallsofIvy 5 1,951 Does anyone know how to solve for x in the following equation: x + \sqrt{x} = 6 I don't know how to solve for x... Nov5-09 03:43 AM HallsofIvy 4 804 How do you explicitly solve for x in terms of y using this quadratic formula? y = 2x2 + x I need to solve for x... Nov5-09 03:36 AM HallsofIvy 2 1,355 would in = an infinite amount of real possibilites if n is complex. considering that 1+0i is still a complex number,... Nov4-09 05:26 AM slider142 4 948 Ive encountered this limit in a book ive been reading. \lim_{t_c \rightarrow 0} \frac{1}{t_c} \int_0^{\infty}... Nov4-09 04:44 AM muballitmitte 1 1,154 If you have dv/dt you say to yourself its the derivative of v with respect to t. But in an example of deriving the... Nov4-09 04:01 AM HallsofIvy 9 1,089 How to prove the following inequality: for complex z such that Re z < 0 : \left| e^z-1\right| < \left| z\right| ? Nov4-09 02:14 AM smyroosh 2 934 nm, made a logical error. back to the drawing board. Nov3-09 10:53 PM TaylorWatts 0 684 Hi: ____________________________________________________________________ Added Nov.3, 2009 (For anyone who can't... Nov3-09 03:30 PM JG89 1 1,448 So I'm supposed to do this but is it just me or is it too hard to do this analytically? (I put it into wolfram online... Nov3-09 07:56 AM Pere Callahan 1 2,271 Please help required with this integral: (x/(x-a))^0.5 where "a" is a start distance of 10^-3 and the final distance... Nov3-09 07:20 AM Per Oni 3 950 Is it true that every open set contains a compact set? Nov3-09 06:42 AM g_edgar 3 2,048