# Lesson Plan: The Argument of a Complex Number Mathematics

This lesson plan includes the objectives, prerequisites, and exclusions of the lesson teaching students how to identify the argument of a complex number and how to calculate it.

#### Objectives

Students will be able to

- understand that the argument of a complex number, , is the angle that the line from the origin to makes with the positive real axis,
- understand that the argument of a complex number is measured in a counterclockwise direction,
- understand that the principle argument is usually given in radians in the range ,
- find the argument of a complex number in any of the 4 quadrants using formulas involving arctan,
- understand how to use the properties of the argument of a complex number (or its conjugate) to solve problems.

#### Prerequisites

Students should already be familiar with

- complex numbers in Cartesian form,
- the conjugate of a complex number,
- operations on complex numbers in Algebraic (rectangular or Cartesian) form,
- Argand diagrams.

#### Exclusions

Students will not cover

- complex numbers in exponential form,
- complex numbers in polar form.