Using a simple trigonometric limit, we provide an intuitive geometric proof of the Singular Value Decomposition of an arbitrary matrix.

Given that the sine and cosine functions of a real variable can be interpreted as the coordinates of points on the unit circle, the author of this article asks whether there is something similar for complex variables, and shows that indeed there is.

Discusses whether a map can be constructed using only the distances between 15 selected cities. Concepts used in the discussion come from geometry, matrix theory and trigonometry. (PK)