FUNDAMENTAL MATRICES OF THE VARIATIONAL SYSTEMS FOR THE NONLINEAR SYSTEMS WITH A SMALL PARAMETER

We show that $\frac{{\partial}x}{{\partial}{\gamma}}(t,{\tau},{\gamma},{\lambda},{\varepsilon})$ is a fundamental matrix of the variational system $\dot{y}=fx(t,x(t,{\tau},{\gamma},{\lambda},{\varepsilon}),{\lambda},{\varepsilon})y$ corresponding to the solution $x(t,{\tau},{\gamma},{\lambda},{\varepsilon})$ of $\dot{x}=f(t,x,{\lambda},{\varepsilon})$.