In that particular module, we covered foundational methods and

looking at how to analyze and combine series and parallel resistors,

using Kirchhoff's voltage laws, voltage divider, current divider.

And we also introduced several systematic solution methods, Mesh analysis,

Node analysis, Thevenin and Norton Equivalents, and Superposition.

Now, it's important because when we did all of these methods,

we were looking at purely resistive circuits.

And when we introduce impedances,

we said an impedance can be treated like a complex resistor.

So in other words, we can apply all of these methods for

AC analysis as long as we're willing to work with complex resistors.