# Lesson 9More Hidden IdentitiesPractice Understanding

In the diagram, complex numbers have been graphed as vectors. Rewrite each complex number as a point in the form .

graphs as

graphs as

graphs as

### 4.

Graph the complex numbers as vectors on the diagram.

### 5.

The magnitude of a complex is its modulus. It is symbolized by the notation where .

Find the modulus of each of the complex numbers.

## Set

Solve the following trigonometric equations. Write your answer(s) in the form ( , where represents the interval between successive solutions and is any integer. Note: sometimes the next solution can be described as just or some other interval, instead of .)

## Go

Use the graph to find all of the values for when , for the given equation. Write your answer(s) in the form , where represents the interval between successive solutions.

### 16.

Use the unit circle to explain the solutions you found in problem 15.

### 17.

Use the graph to approximate the points of intersection of the graphs of and .

### 18.

The scale on the -axis in the graph of problem 18 is . The scale in the graph of problem 20 is . Yet the units on both axes is radians.

#### a.

Label the graph with the approximate location of and .

#### b.

Label the graph with the approximate location of , , , and .