# Complex and Imaginary Numbers

In this lesson I’m going to teach you about the complex number system.  The lesson will cover a lot of concepts and it’s a little long so make sure you set aside a good time to watch it.  So what is a complex number?  Well let’s first look at another system before we answer that question- the real number system.  All the numbers you have studied in math until now have been real numbers- numbers you can plot on a number line.  These would include integers, fractions, decimals, whole numbers, positive and negative numbers, square roots and rational/irrational numbers. However, the real number system is not the only number system in math especially more advance math. So back to our question- what is a complex number? Well let’s look at an example of a complex number, the square root of -16.  If you have your calculator try to find the square root of “negative 16”.  Most likely, your calculator gave you an error message because it does not understand- it’s thinking in terms of real numbers.  You see anytime we try to take the square root of a negative number we get numbers called “imagery” numbers and these make up the complex number system.  My lesson video will cover this more clearly and much, much more!  So be ready to take a lot of notes and practice is essential if you really expect to master all the skills we will study.