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- Dini Expansion
- Dini's Surface
- Dini's Test
- Dinitz Problem
- Diocles's Cissoid
- Diophantine Equation
- Diophantine Equation--10th Powers
- Diophantine Equation--5th Powers
- Diophantine Equation--6th Powers
- Diophantine Equation--7th Powers
- Diophantine Equation--8th Powers
- Diophantine Equation--9th Powers
- Diophantine Equation--Cubic
- Diophantine Equation--Linear
- Diophantine Equation nth Powers
- Diophantine Equation--Quadratic
- Diophantine Equation--Quartic
- Diophantine Quadruple
- Diophantine Set
- Diophantus Property
- Diophantus' Riddle
- Dipyramid
- Dirac Delta Function
- Dirac Matrices
- Dirac's Theorem