Introduction to Calculus: What is a Derivative?

00:00 Introduction & Setting up the Function y=f(x) 01:01 Average Rate of Change: The Slope Between Two Points 02:17 The Concept of Limits: What if Delta x Approaches Zero? 03:04 Defining the Derivative f'(a) (The Differential Coefficient) 04:04 Geometric Interpretation: Slope of a Tangent Line