Recent content by veneficus5

Homework Statement Latex takes me forever so I'm going to take a picture Homework Equations The Attempt at a Solution I'm having issues with integrating functions. There seems to be this (x-x0) term that crops up everywhere. Last time it was (t - tau). It's always (variable -...

isn't it -1? edit: oh got it 2nd edit: nope still got -1 I approached from both possible y's

Has something to do with that one of them is your homogeneous solution (ie if you put it in, you will get LHS = 0) It also has something to do with a product rule between t and e^2t, but I am not sure how it all works out.

Homework Statement In the midst of Forced Vibrating Membranes and Resonance Utt = c^2*delsquared(U) + Q(heat source) Arrive at eigenfunction series solution where the coefficients are given by d^2/dt^2 (A_n) + c^2*lambda_n*A_n = q_n Homework Equations according to the book, I am supposed to...

actually Unrest I am now interested in your numerical method. My professor said that doing it numerically would suffice.

1) 1 + x/h^2 is x/h^2 as x gets larger. Now you have 1 / (x/h^2)^1/2 which is h/x. Try x = 10000 H = 5. => 4.99E-4. 5/10000 = 5E-4 2) (H/x)^2 is 1/x^2 as x gets larger? Then 1 + 1/x^2 is 1 as x gets larger. Now you have 1 / 1^1/2 which is 1. Try x = 1000 H = 5. => .999.

If you look at the graphs on top of each other, sin x starts out the same as x. So it makes sense that as x approaches 0, one thing divided by the same one thing should be 1. Thanks for the pronunciation tip. I never knew how to say L'Hopitals.

ah I got it. Pretty clever. Thanks So I can think of el hopital taking the slope of the top and bottom of the fraction. For sin x / x, sin x superimposed upon x makes it clear that it is 1. It also sort of makes sense how el hopitals only works when there is a singularity on the bottom...

Ya I got to them, and I understand the series answer. So I take the derivative of \int_0^1 \cos(x t) dt wrt x. This gives me \int_0^1 \sin(x t) / -t dt. Then what do I do. Sorry it's not obvious :(

Ah thanks, but I don't understand the last one with the cos.

Homework Statement Why is sin x / x at x = 0 equal to 1? Homework Equations d/dx (sinc(x)) evaluated at x = 0. The Attempt at a Solution El hopital's rule Cos(x)/1, cos(0) = 1 However when looking at the picture of Sinc, http://www.wolframalpha.com/input/?i=sin(x)/x, it...

The purpose of the presentation is to present something relatively new and interesting related to PDEs to my class in about 20 minutes. Even though it should be a stiff bending plate, I think I'll just explain that detail at the beginning of the presentation and look at the membrane version...

Well if I do it numerically, I'll have to come up with the method. I am doing a presentation on it. I should have stated that.

Hello physics enthusiasts! I was looking for resources, and stumbled upon these awesome forums. I am looking for how to solve the helmholtz equation / wave equation on a figure 8 type shape. I wanted to find the resonant frequencies of a classical guitar. Would this work? I am considering...