Using Sqrt[x_]/y_ ->
- To: mathgroup at smc.vnet.net
- Subject: [mg7314] Using Sqrt[x_]/y_ ->
- From: sergio at scisun.sci.ccny.cuny.edu (Sergio Rojas)
- Date: Fri, 23 May 1997 01:41:48 -0400 (EDT)
- Organization: City College Of New York - Science
- Sender: owner-wri-mathgroup at wolfram.com
(*--> Hello folks, *)
(*---> In Mathematica 2.2, using: *)
Needs["Calculus`DSolve`"]
answer = DSolve[{(x +e*f[x])*f'[x] + f[x] == 1, f[1]==2}, f[x],x]
f1[x_] = Expand[f[x] /. answer[[1]]] /. Sqrt[x_]/y_ -> Sqrt[Expand[x/y^2]]
(*---> one can get: *)
(*-----------------------------------------------------------
2 2
x 2 e + 4 e + 2 e x + x
Out[36]= -(-) - Sqrt[-----------------------]
e 2
e
------------------------------------------------------------*)
(*---> 1.- How can one use := instead of = in the f1[x_] definition *)
(*---> 2.- Why Expand does not work inside Sqrt[...] *)
Sergio Rojas
E-mail: sergio at scisun.sci.ccny.cuny.edu