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Re: Differential equation with several variables in the function


you must try to formulate your problem as simply a s possible. If your 

consider f[x+y] then you should introduce a new variable z=x+y and 

formulate your problem in terms of the one variable function f[z].

If you would give a simple example of your problem, you may get more 

specific answers.

hope this helps, Daniel

petterbe at wrote:

> Hi,

> I have a differential equation were the function F[.] depends on

> several varibles,x,y,z. I would like to solve the differential

> equation for the entire function. However, I only manage to get

> solutions from Mathematica if I have one variable in the function. For

> example DSolve[egn==0, F[x],x]. If i try to solve for my entire

> function F[x+y+z] using DSolve[egn==0, F[x+y+z],x] or even just add 1

> to the function (F[x+1]) I get the error message "DSolve::litarg: To

> avoid possible ambiguity, the arguments of the dependent variable in

> XXX should literally match the independent variables."


> Does anybody have some good suggestions?

> Thanks


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