] and differentiable on the open interval a b

] and differentiable on the open interval a b (where f ( a ) and f ( b ) are not necessarily equal). Then there is at least one point c a b ∈ ( such that ′ ( ) = ( ) − f b f a • Taylor’s series Let f x ( ) be a function infinitely differentiable at x . Then f x ( ) can be expanded as a series in an interval ( ), - e e e > ,of the form f a ( ) = ) = ( ) + ′ ( ) ) + ∞