Cauchy–Schwarz inequality for integrals
, 
are real functions, then 
if all these integrals exist. This the Cauchy-Schwarz inequality applied to the space of square-integrable functions.
- descriptive statistics
- design methods
- destinations
- detachment, law of
- determinant
- determinantal rank
- determine
- deterministic model
- developable surface
- deviation
- devil's staircase
- df
- diagonal
- diagonal
- diagonal
- diagonal argument
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- diagonalizable
- diagonally dominant matrix
- diagonal matrix
- diagram
- diameter
- diameter
- diameter of a set
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