  Math Central - mathcentral.uregina.ca  Quandaries & Queries    Q & Q    Topic: integrating   start over

5 items are filed under this topic.    Page1/1            Approximating an integral 2005-01-27 From A student:i used excel to find the area under a graph instead of integrating the function the analytical way. These are the different answers i got with different width of the x-values, the smaller the x-increment gets the more precise the area is when compared to the answer obtained the numerical way. I have trouble seeing why the answers i get is getting bigger and bigger and not smaller can someone plz explain?Answered by Penny Nom.     An ODE 2004-11-10 From David:I have a question that i really cant do, it is as follows: The ODE dy/dx + 0.5y = 0.5e^(-1.5x) ; y(5) = 2 Solve the ODE subject to the given condition using exact methods and evaluate the solution y for x = 5 x=5.2 x=5.4 x=5.6 x=5.8 x=6Answered by Harley Weston.     The integrating factor method 2004-08-05 From A student:Whilst using the integrating factor method, I am required to integrate a function multipled by another function. say f(t) = exp(kt) and some other function g(t); where exp = exponential and k is some constant. Integral f(t)*g(t) dt or Integral exp(kt)*g(t) dt What would the result of this integral be? I have never met an integral like this before. Would it simply be exp(kt)*g(t)/k? More specifically, the problem and my attempted answer is in PDF format: In my attempted solution, I am unsure about the last two lines I have written out, as it relates to integrating a function multipled by another function.Answered by Harley Weston.     Integrating e^x sin(x) 2003-05-03 From Lech:I am having trouble integrating the following expression by parts: ex sin(x) I used the integrator at http://www.integrals.com/ to find the solution, ? 1/2 ex cos(x) + 1/2 ex sin(x). This is easy to confirm by differentiation, however I am confounded as how to arrive at the answer. Answered by Penny Nom and Claude Tardif.     Integrating x^x 2002-06-18 From Jeremy: I am a student at the University of Kansas and I am wondering if there is a general anti-derivative for x x (i.e. the integral of x x dx)? I've looked in a bunch of Table of Integrals and have found nothing (can you guys find it?), so I'm sort of wondering if this may be a research type question. Answered by Claude Tardif.      Page1/1    Math Central is supported by the University of Regina and The Pacific Institute for the Mathematical Sciences.    about math central :: site map :: links :: notre site français