#### Engineering Design

The purpose of this section is to show one application of sinusoidal signals to
engineering design.

#### Review of Complex Numbers

This section aims to introduce two different ways we represent complex numbers:
Cartesian coordinates, and Polar coordinates. We often use complex numbers in
Cartesian coordinates when we discuss impedance or admittance. We often use
complex numbers in polar coordinates to discuss magnitude and phase of voltages,
currents, transfer functions, and Bode Plots. We can also represent sinusoidal signals
with complex numbers with phasors. It is critically important that we understand
this chapter.

#### Operations with Complex Numbers

The purpose of this section is to review arithmetic operations with complex numbers.
We use complex numbers to describe circuits. When we solve circuits to find voltages,
currents, and power, we often encounter addition, subtraction, multiplication,
division, and the complex conjugate of complex numbers.

#### Euler’s Formula

The purpose of this section is to relate sinusoidal signals and complex numbers using
Euler’s formula.