31.5.2 What Multiplication Really Does: Add the Angles, Multiply the Lengths
Core ideaPicture this: multiply two complex numbers and the arrow lengths multiply while the arguments add — multiplying by a complex number is just one rotation plus one scaling
Module goal. We upgrade a complex number from a "coordinate address" to a "length plus direction," revealing that multiplication and division are really rotation and scaling — and laying groundwork for deeper material to come