This lecture covers the temporal derivative of a product of functions, including the derivative of the product f * g, where f and g are scalar or vector functions of time. It explores the variation of the product f * g between two time instants and the calculation of the derivative using limit definitions. Additionally, it discusses the derivative of a quotient of functions, providing examples of algebraic products of scalar functions and the scalar product of vector functions. The lecture concludes with the calculation of derivatives for various function products.