Calculus: MVT for Derivatives

Objectives

• Interpret the statement of the Mean Value Theorem in terms of its graphical representation
• Use slopes of secant and tangent lines to explain the relationship between average and instantaneous rates of change demonstrated by the MVT
• Identify functions and/or intervals for which the MVT cannot be applied

Vocabulary

• secant line
• tangent line
• average rate of change
• instantaneous rate of change

About the Lesson

This lesson uses a graphical representation of the Mean Value Theorem (MVT) to demonstrate how the theorem relates information about the average rate of change of a function to an instantaneous rate of change. As a result, students will:

• Change the endpoints of intervals and relate the changes in the slopes of secant lines to the average rate of change.
• Observe that for the first two functions provided there is always a point in the intervals where the tangent line is parallel to the secant line connecting the endpoints, supporting the conclusion of the MVT.
• Observe a function that is not everywhere differentiable to note when the conclusion of the MVT may not hold.