MathGroup Archive 2006

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

Search the Archive

Re: Solving the differential equation

  • To: mathgroup at smc.vnet.net
  • Subject: [mg65490] Re: [mg65472] Solving the differential equation
  • From: "David Park" <djmp at earthlink.net>
  • Date: Wed, 5 Apr 2006 06:55:30 -0400 (EDT)
  • Sender: owner-wri-mathgroup at wolfram.com

You could do the following.

Clear[y]
y[f_][x_] = y[x] /. First@DSolve[y'[x] == f[x], y, x]
C[1] + Integrate[f[K$86], {K$86, 1, x}]

f has been defined as a parameter for the y function. It can be entered as
the name of a predefined function or as a pure function.

y[Sin][x]
C[1] + Cos[1] - Cos[x]

y[#^2 &][x]
-(1/3) + x^3/3 + C[1]

David Park
djmp at earthlink.net
http://home.earthlink.net/~djmp/


From: Subbu [mailto:subbaraokommuri at gmail.com]
To: mathgroup at smc.vnet.net


Hi,

Can you please tell me the answer for the fallowing

Suppose I am solving a Differential eqn like

DSolve[y`[x]==f[x],y,x]

Suppose, I dont know the form of f[x] while solving the equation but
mathematica is giving some solution. After obtaining that solution
suppose if I know the form of f[x] how can I get the solution for 'y'
as a function of x.

Thank you.



  • Prev by Date: Re: simultaneous nonlinear regression of a lot of data
  • Next by Date: Integrate problem
  • Previous by thread: Re: Solving the differential equation
  • Next by thread: Re: Problem with Infinite products--> further modulo 12 prime functions