Extended data:
Definition of power series:
Let U 1 (x), U2 (x), ..., UN (x), ... be function columns be defined on the interval I, then the expression
( 1)
It is cal that series of function term defined on the interval I. ..
If each un(x) in the formula (1) is a power function defined on the interval (-∞,+∞), then the function term is a series.
(2)
It is called a power series, where x0 is a constant, a0, a 1, ..., and a coefficient called a power series.