Chapter 12
Taking the Complexity Out of Complex Numbers
IN THIS CHAPTER
Defining imaginary and complex numbers
Writing complex solutions for quadratic equations
Determining complex solutions for polynomials
Mathematicians define real numbers as all the whole numbers, negative and positive numbers, fractions and decimals, radicals — anything you can think of to use in counting, graphing, and comparing amounts. Mathematicians introduced imaginary numbers when they couldn’t finish some problems without them. For example, when solving for roots of quadratic equations such as 
, you quickly discover that you can find no real answers. Using the quadratic formula, the solutions come out to be
The equation has no real solution. So, instead of staying stuck there, mathematicians came up with something innovative. They made up a number and named it i.
The square root of can be replaced with ...
Get Algebra II Essentials For Dummies now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.
