in C t can calculate a definite integral of a function. f(x)dx = F(b)-F(a) dF where F is the antiderivative off-ie. f find the antiderivative. For example, if f-2x then F = x2. However, if the function is more complicated, it's not possible to easily find the antiderivative - this is called a nonelementary antiderivative. obvious. If the function f is simple, it's possible to dx For example, if f=sin (r), the antiderivative is not