Orthogonal Basis
A Basis of vectors 
which satisfy
where
, 
are constants (not necessarily equal to 1) and 
is the Kronecker Delta.See also Basis, Orthonormal Basis- Quasitruncated Small Stellated Dodecahedron
- Quasi-Unipotent Group
- Quasi-Unipotent Problem
- Quaternary
- Quaternary Tree
- Quaternion
- Quattuordecillion
- Queens Problem
- Queue
- Queuing Theory
- Quicksort
- Quillen-Lichtenbaum Conjecture
- Quincunx
- Quindecillion
- Quintet
- Quintic Equation
- Quintic Surface
- Quintillion
- Quintuple
- Quintuple Product Identity
- Quintuplet
- Quota Rule
- Quota System
- Quotient
- Quotient-Difference Algorithm