Khan Academy: "Calculating Slope of Tangent Line Using Derivative Definition"

Watch this video on limits as the slopes of tangent lines.

An earlier Khan Academy video (not used in this course) defined the limit that gives the slope of the tangent line to a curve as \( y = f(x) \) at a point \( x = a \) and called it the derivative of \( f(x) \) at \( a \). The text will introduce this term in Unit 3.