# AP Calculus AB Unit 4: Contextual Applications of Differentiation

The eight lessons in AP Calculus AB Unit 4 focus on the contextual applications of differentiation. Each lesson includes an overview, an instructional video, practice problems, and solutions. Scholars first review the connection between derivatives and rates of change and learn how to interpret the derivative in contextual situations. Another lesson looks at straight-line motion. Scholars learn how position, velocity, and acceleration are related by derivatives before using the concept to solve problems. Pupils also learn about rates of change not related to motion, how to write equations that show a relationship between variables, and then apply implicit differentiation to them. Other lessons demonstrate how to solve related rate problems and how to approximate function values. Lâ€™Hopitalâ€™s rule is the focus of the last lesson. To end the unit, scholars work on a set of practice problems to test their understanding of the applications of derivatives.