Re: newbie: diff equation

*To*: mathgroup at smc.vnet.net*Subject*: [mg96913] Re: [mg96886] newbie: diff equation*From*: "Ned Lieb" <okty.gy.ned at gmail.com>*Date*: Fri, 27 Feb 2009 06:12:03 -0500 (EST)*References*: <200902261301.IAA26650@smc.vnet.net>

You have to use two equals signs instead of one when inputting a differential equation. -----Original Message----- From: Mike [mailto:atkins1976 at yahoo.com] Sent: Thursday, February 26, 2009 8:01 AM To: mathgroup at smc.vnet.net Subject: [mg96913] [mg96886] newbie: diff equation My problem is very simple, I'm sure someone can help me out quickly. I am trying to solve some systems of differential equations a bit like a particle in a box (QM) so I started with this basic problem which I know how to solve just to make sure I am entering everything ok, but I can't even get it to work. I want to solve f''[x]= - m^2 f[x] with f[0] = 0 and f[Pi] = 0 this is obviously only solvable with the condition on m being integer but if I do DSolve on the above with the boundary conditions I just get f=0. How can I get mathematica to solve this and give me the conditions on m? I need to solve much more general problems of this type. I hope someone can help. Many thanks

**References**:**newbie: diff equation***From:*Mike <atkins1976@yahoo.com>