Elliptic Point
A point p on a Regular Surface 
is said to be elliptic if the Gaussian Curvature
or equivalently, the Principal Curvatures 
and 
have the same sign.
References
Gray, A. Modern Differential Geometry of Curves and Surfaces. Boca Raton, FL: CRC Press, p. 280, 1993.
- Bisection Procedure
- Bisector
- Bishop's Inequality
- Bishops Problem
- Bislit Cube
- Bispherical Coordinates
- Bitangent
- Bit Complexity
- Bivariate Distribution
- Bivector
- Biweight
- Blackman Function
- Black-Scholes Theory
- Black Spleenwort Fern
- Blancmange Function
- Blaschke Conjecture
- Blaschke's Theorem
- Blecksmith-Brillhart-Gerst Theorem
- Blichfeldt's Lemma
- Blichfeldt's Theorem
- BLM/Ho Polynomial
- Bloch Constant
- Bloch-Landau Constant
- Block
- Block Design