#### What are complex numbers?

A complex number can be written in the form a + b*i*
where a and b are real numbers
(including 0) and *i* is an imaginary number.

Therefore a complex number contains two 'parts':

- one that is real
- and another part that is imaginary

**note:** Even though complex have an imaginary part, there
are actually many real life applications of these "imaginary" numbers including
oscillating springs and
electronics.