vector
A vector may be considered as the position vector 
of a point P from an origin O or as a translation vector, a movement of space. In this way the zero vector may considered as the position vector of the origin or as no translation. The distinction between a vector and a coordinate vector may in some contexts be important, especially if more than one coordinate system is being used; in this case the same vector may have different coordinates in the two systems.
With a given coordinate system, a vector can be identified with an ordered pair (x,y) or ordered triple (x,y,z), whether considered as a position vector or a translation vector. This definition can easily be generalized to other dimensions. Addition and scalar multiplication may be defined componentwise. Other operations are important (see scalar product, vector product).
- transition matrix
- transitive
- transitive relation
- translation
- translation of axes
- transportation problem
- transpose
- transposition
- transversal
- transverse axis
- transverse component
- transverse wave
- trapezium
- trapezium rule
- trapezoidal rule
- travelling salesman problem
- traversable graph
- tree
- trefoil
- trend
- tri-
- trial
- trial and improvement
- triangle
- triangle inequality