We use a direct variational method in order to investigate the dependence on parameterrnfor the solution of the following Du_ng type equation with Dirichlet boundaryrnconditionsrnx(t) + r(t)x_ (t) Fx(t; x(t)) f(t) = 0rnx(0) = x(1) = 0rnand we observe that some outline of variational approach, in order to use this method.rnKey Words and phrases:Dirichlet boundary problem,Du_ng equation andrnLower semicontinuity