/ck/ - Food & Cooking

>>8995484
it's a transformation from Cartesian to polar coordinates
the middle part is the change of coordinates and the Jacobian matrix and its determinant

if girl is a graph, the one on the top is the original, plotted using Cartesian coordinates, and the one on the bottom is the graph after being transformed

also notice, the original has sort of a rectangular shape to it. As such, after a change of coordinates to polar coordinates, it looks somewhat like a polar rectangle (pic), which is just a rectangle after such a transformation has been applied to it

I don't know what the color change is referencing