Course: Trigonometry
Topic: Complex, Parametric, and Polar Forms
Subtopic: Trigonometric Form of Complex Numbers


In an intermediate algebra course you wrote Complex numbers in standard (a+bi) form. But this is not the only way to express them. Engineers typically use the Trigonometric Form of a Complex Number instead. Our goal today is to learn to write complex numbers in trigonometric form, plot them on a Complex plane, and convert them between standard and trig form.


By the end of this topic you should know and be prepared to be tested on:


Terms you should be able to define: Complex plane, modulus / opposite / conjugate / argument (all of a Complex number), trigonometric form, the acronym "cis"

Supplementary Resources

Performing operations with complex numbers manually is not difficult, but if you want to do so electronically I have directions for Texas Instruments calculators TI-84, TI-86, and TI-89 here: Prof. Keely's Calculator Guide: Complex Numbers.