Abstract:
In the theory of the matrix equation $\dot{X}=A(t)X$, an important role is played by the well-known representation of the solution in the form of a series. In the case of a scalar equation of the th order, it is also interesting to obtain a representation of the solution in the form of a scalar series the terms of which are constructed using the coefficients of the original equation. In this paper, various representations of a fundamental system of solutions of a homogeneous quasi-differential equation of the th order in the form of scalar series whose terms are constructed using the coefficients of the original equation are studied. For example, in the form of such series, representations of the elements of the fundamental system of solutions of the Bessel equation considered on the interval $[\vartheta,+\infty)$, where $\vartheta>$ 0, are constructed.
Key words:quasi-differential equation, Cauchy function, fundamental system of solutions, sum of the series, initial approximations, Bessel equation.
