Explanation

A complex number can be written in polar form:
z = r(cos θ + i sin θ)

Where:

• r = modulus

• θ = argument

This form connects complex numbers with trigonometry.

Quiz

1. What does r represent?

2. What does θ represent?

3. Write the general polar form.

4. Is polar form useful for multiplication?

5. Does polar form use sine and cosine?

Answer Key

1. Modulus

2. Angle

3. r(cos θ + i sin θ)

4. Yes

5. Yes