Definition of Indefinite Integral

This lecture covers the definition of the indefinite integral, where a primitive of a function f is a function F such that F'(x) = f(x) for all x in the interval (a, b). It also discusses the properties of primitives, emphasizing that two primitives of a given function differ by a constant. The lecture further explores the concept of the indefinite integral of f as the set of all primitives of f, providing notations and applications of this integral.