Explanation

Multiplying complex numbers in polar form has a geometric meaning.

When multiplying:

• Moduli multiply

• Arguments add

Geometrically:

• The result is a stretch and rotation

Quiz

1. What happens to the modulus when multiplying?

2. What happens to the arguments?

3. Does multiplication rotate points?

4. Does it stretch or shrink?

5. Is this easier in polar form?

Answer Key

1. They multiply

2. They add

3. Yes

4. Yes

5. Yes