Explanation

A complex number has the form:
z = a + bi

Where:

• a = real part

• b = imaginary part

• i = √(−1)

The complex plane is like the coordinate plane:

• Horizontal axis = real axis

• Vertical axis = imaginary axis

The complex number a + bi is graphed at the point:
(a, b)

Example:
z = 3 − 2i → point (3, −2)

Quiz (5 Questions)

1. What is the real part of 4 − 7i?

2. What is the imaginary part of −2 + 5i?

3. Where is the real axis located?

4. Plot the complex number 1 + 3i as a point.

5. What does the vertical axis represent?

Answer Key

1. 4

2. 5

3. Horizontal axis

4. (1, 3)

5. Imaginary numbers