Recent content by neptunecs

Hello all: I'm interested in minor planet.Could you tell me how to calculate the orbit of a minor planet accurately? Is there any software to calculate it? And how to get the latest information of the minor planets?Any websites of famous international institutes who observe and...

https://www.physicsforums.com/attachment.php?attachmentid=7298&stc=1&d=1152433684

I doubt that the Symbolic Math Toolbox is installed,and I doubt that Toolbox can solve my problem

Thank you. I find that I have the Symbolic Math Toolbox installed,I will have a try soon.

Hi,I have a problem in Matlab programme,I want to calculate the derivative of a expression by matlab,but there are some abstract functions in that expression. for example:f=R(t)*cos(t),I want calculate d=diff(f,t),but I don't know how to deal with the abstract function R(t),I hope I can...

Thank very much.This solution is particular. my teacher said It's non-convergence thing, too. neptunecs.

Thank you. But the integral does not converge seems strange.Maybe my teacher made a mistake.

R(s)=\int_{-\infty}^{\infty} f(t)f(t+s) dt which f(t)=Acos(wt+f0) Thank for Curious3141's help! neptunecs.

where is LaTex in this forum?I didn't find it.Tell me,please.Thanks.

Hi,How to calculate this integral: which I have ever calculated it and the result(R(s)) is ∞,but I don't think it's right,I'm not sure with it. Thank you for your help! neptunecs.

Thank you very much! I will read that paper soon,but I think it's difficult for me,because I know only a little about Number Theory ,I major in theoretical physics... But thanks for your answer which make me know that this problem has been solved. Neptunecs.

Thank you very much. It's seems that this problem haven't been solved in Number Theory,it's hard to find a function s(N) to discript the int solutions of N=x^2+y^2+z^2, right? Thanks for your opinion and information.

Hi N=a^2+b^2+c^2, a.b.c.N are all integers(>0),I am wondering how many solves for each N. Have this problem been solved in Number Theory? This problem is originate from a quantum mechanics question I met. thanks for any advice. neptunecs