tractrix
The surface of revolution formed by rotating the tractrix about the x-axis is called the tractoid. It has constant Gaussian curvature –1.
- direct isometry
- directly proportional
- direct product
- direct proof
- directrix
- direct sum
- direct variation
- Dirichlet beta function
- Dirichlet function
- Dirichlet, Peter Gustav Lejeune
- Dirichlet problem
- Dirichlet's approximation theorem
- Dirichlet series
- Dirichlet's test
- disc
- disc of convergence
- disconnected
- discontinuity
- discontinuous function
- discrete
- discrete data
- discrete Fourier transform
- discrete logarithm
- discrete mathematics
- discrete metric