Complete your review by going over the basic facts of integration. After a simple example of integration by substitution, turn to definite integrals and the area problem. Reacquaint yourself with the fundamental theorem of calculus and the second fundamental theorem of calculus. End the episode by solving a simple differential equation.

In the first of three episodes on differential equations, learn various techniques for solving these very useful equations, including separation of variables and Euler’s method, which is the simplest numerical technique for finding approximate solutions. Then look at growth and decay models, with two intriguing applications.

Continue your study of differential equations by examining orthogonal trajectories, curves that intersect a given family of curves at right angles. These occur in thermodynamics and other fields. Then develop the famous logistic differential equation, which is widely used in mathematical biology.

Investigate linear differential equations, which typically cannot be solved by separation of variables. The key to their solution is what Professor Edwards calls the “magic integrating factor.” Try several examples and applications. Then return to an equation involving Euler’s method, which was originally considered in an earlier lesson.