Consider the complex number **z = a + bi** and the point **P** that represents him.

The distance of **P** until the origin is called **module **in **z**, and represented by . From the highlighted rectangle triangle we have:

The angle measurement , formed by with the abscissa axis, measured counterclockwise, is called **argument **of the complex **z**. note that .

It is indicated:

= arg (z) |

Note that:

and

**Example**

Determine the modulus and the argument of .

*Resolution:*

**Module:**

**Argument:**