where T (f(x)) is the Taylor series for f(x). The integral equation (3.239) will
be converted to a traditional integral in (3.240) or (3.241) where instead of
integrating the unknown function u(x), terms of the form tn,n 0 will be
integrated. Notice that because we are seeking series solution, then if f(x)
includes elementary functions such as trigonometric functions, exponential
functions, etc., then Taylor expansions for functions involved in f(x) should
be used