  In the work we use integral formulas for calculating the monodromy data for
the Painlev\'e-2 equation. The perturbation theory for the auxiliary linear
system is constructed and formulas for the variation of the monodromy data are
obtained. We also derive a formula for solving the linearized Painlev\'e-2
equation based on the Fourier-type integral of the squared solutions of the
auxiliary linear system of equations.
