Groups
Category
Level
Eigendecomposition expresses a matrix as a change of basis times a diagonal scaling, revealing its natural stretching directions.
Computability theory studies the boundary between what can and cannot be computed by any algorithm.
The Halting Problem asks whether a given program P will eventually stop when run on input x; there is no algorithm that correctly answers this for all P and x.
Eigenvalue decomposition rewrites a square matrix as a change of basis that reveals how it stretches and rotates space.