AT A-LEVEL: in Year 1 of A-level we seem to be fine with the regular $x,y$ or “Cartesian” equations of curves e.g. $y=x^2$ is a parabola, or $(x-a)^2+(y-b)^2=r^2$ is a circle. And then in Year 2: BAM! along comes the Parametric Equation of a curve! Why bother? Simply because it allows us to describe and analyse a much larger class of curves! Here’s a simple example:
CAT ON LADDER CASE 1: Tiptoes the Cat sees a ladder propped up against a wall, leaps up onto the middle rung (halfway up the ladder) and settles down for a good catnap. To his horror,