On nonequidistant difference formulae of the Hermite type


Dragoslav Herceg




In this paper a procedure for determination of nonequidistant difference formulae of the Hermite type \[ um_{j=0}^p(h^{-k}a_jx(t_i+s_jh)+b_jx^{(k)}(t_i+s_jh))=0\;(h^{m+1-k}), \] and a corresponding formula for $k=2$, $p=3$, $m=5$ are given. The obtained formula can be used for a discretion of the equation from (KP) at points $t_i(i=1,2,\dots,n-1)$ of an arbitrary nonequidistant grid $I_h$. A special case of this formula, when $I_h$ is an equidistant grid, is a well known formula [5], [6] of the type (1) with coefficients from (2).