Complex Numbers

Our last stop on this algebra refresher is complex numbers. These numbers are important in modern mathematics and are used by mathematicians very often. They are also used in electric circuits and in the study of radio waves. So if it weren’t for these numbers, we might not be able to talk on cell phones or listen to the radio!


Complex numbers are numbers in the form a + bi, where a and b are real numbers, and i is the imaginary unit. a is the real part of such number and bi is the imaginary part of a complex number.

How They Came into Existence

Throughout the history of civilization, new kinds of numbers have been ...

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