The Basics of Complex Numbers
Concept

The Imaginary Unit

The imaginary unit is the principal square root of that is, From this definition, it can also be said that

Imaginary Unit
or

The imaginary unit can also be regarded as a solution to the equation
The imaginary unit allows to rewrite the square root of any negative number. Once replaces the square root of the square root of the remaining positive number can be evaluated as usual.

The above property is true only when Here are some examples of how to use the property to simplify radical expressions.
The combination of real numbers and any expression of the form with creates a new set of numbers called imaginary numbers.
Exercises