Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2005
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2005

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: How do I get a DSolve'd function

  • To: mathgroup at smc.vnet.net
  • Subject: [mg54407] Re: [mg54384] How do I get a DSolve'd function
  • From: Bob Hanlon <hanlonr at cox.net>
  • Date: Sun, 20 Feb 2005 00:08:09 -0500 (EST)
  • Reply-to: hanlonr at cox.net
  • Sender: owner-wri-mathgroup at wolfram.com

Clear[f];
f[x_] = f[x] /. 
      DSolve[{f'[x]==-3f[x],f[0]==10},f,x][[1]];

f[x]

10/E^(3*x)


Bob Hanlon

> 
> From: skirmantas.janusonis at yale.edu (Skirmantas)
To: mathgroup at smc.vnet.net
> Date: 2005/02/19 Sat AM 02:33:01 EST
> To: mathgroup at smc.vnet.net
> Subject: [mg54407] [mg54384] How do I get a DSolve'd function
> 
> I hope this is the last question for now.
> 
> I can solve a differential equation and plot it by doing something
> like this:
> 
> sol=DSolve[{f'[x]==-3f[x],f[0]==10},f,x]
> Plot[f/.sol,{x,0,10}]
> 
> But how do I get the function f[x] itself? I want to be able to input
> f[x] and get its definition. Or do Plot[f[x],{x,0,10}]. Or define
> y[x_]:=f[x]^2.
> 
> f[x]/.sol or f[x_]:=f[x]/.sol or f[x_]:=sol[[n,n,n]] do not work.
> 
> What if the solution is a function with many variables, say u[x,y,z]?
> What's the correct way to "get" it?  
> 
> 


  • Prev by Date: Re: Why does Inverse[M] hesitate?
  • Next by Date: Re: How do I get a DSolve'd function
  • Previous by thread: Re: How do I get a DSolve'd function
  • Next by thread: Re: How do I get a DSolve'd function