This series teaches the Laplace transform, a powerful tool for solving differential equations. You will learn how to take the Laplace transform of common functions and use it to turn hard calculus problems into simpler algebra problems. Engineers use this method to study circuits, springs, and control systems. This is advanced material. You should complete calculus and an introduction to differential equations first.
Note: All Khan Academy content is available for free at www.khanacademy.org