6.002 Lecture Notes: Sinusoidal Steady State and the Impedance Method

You’ve probably seen impedance in some context before, perhaps in a physics class, or in some discussions in an introductory lab class. If so, you will remember a few formulas and perhaps how to apply them, but here I’d like to not only explain how to use impedance as a concept, but also why it works. That way, you’ll know when you can apply this method, and when it is not appropriate. The first step in understanding why impedance works is in understanding some simple aspects of the math of sinusoidal functions.