Precalculus: Complex Number Addition

Objectives

• Students will compute the sum of two complex numbers.
• Students will visualize and geometrically describe the sum of two complex numbers.
• Students will compute the absolute value and use trigonometry to find the argument of complex numbers.
• Students will compare the absolute values and arguments of two complex numbers to the absolute value and argument of their sum.

Vocabulary

• complex number
• position vector
• absolute value or magnitude of a complex number
• argument of a complex number

About the Lesson

This lesson involves the addition of two complex numbers.
As a result, students will:

• Compute the sum of specific complex numbers, make a general statement to describe this sum, and characterize the sum geometrically.
• Compute the absolute value and argument of complex numbers.
• Investigate and analyze the sum of two complex numbers with point representations that lie on the same line.