Can't get solutions in output of wolfram mathematica

Question

When I type a function into wolfram mathematica (such as EulerEquations[]) it doesn't output a solution, just outputs the same thing I typed in as input.

Does anyone know how to fix this?

Answer 1

EulerEquations[f,y[x],x] will return the Euler-Lagrange differential equation obeyed from y[x]. You'll probably recall these are associated with a variational problem for the functional f. Try entering Dsolve[%,y[x],x] to get the solution, if that's what you're after.

Also, you may need to load the package Needs["VariationalMethods`"], especially if you're working directly in Mathematica and not on Alpha.