## Complex Numbers:

A complex number in standard form is a + bi, where a and b are real numbers. If b does not equal zero then a + bi is an imaginary number. If a equals zero, then a + bi is a pure imaginary number.

Just as every real number can be plotted on a plane, so can complex numbers. The complex plane contains a horizontal real axis and an imaginary vertical axis.

The absolute value of a complex number z= a + bi is a nonnegative real number defined by:

Just as every real number can be plotted on a plane, so can complex numbers. The complex plane contains a horizontal real axis and an imaginary vertical axis.

The absolute value of a complex number z= a + bi is a nonnegative real number defined by:

This is the distance between z and the origin in the complex plane.