Unit Vector
A Vector of unit length. The unit vector 
having the same direction as a given (nonzero) vector vis defined by
where
denotes the Norm of 
, is the unit vector in the same direction as the (finite) Vectorv. A unit Vector in the 
direction is given by
where
is the Radius Vector.See also Norm, Radius Vector, Vector- Regular Sequence
- Regular Singularity
- Regular Singular Point
- Regular Surface
- Regular Triangle Center
- Regulus
- Reidemeister Moves
- Reidemeister's Theorem
- Reinhardt Domain
- Relation
- Relative Error
- Relative Extremum
- Relatively Prime
- Relative Maximum
- Relative Minimum
- Relaxation Methods
- Remainder
- Remainder Theorem
- Rembs' Surfaces
- Removable Crossing
- Removable Singularity
- Rencontres Number
- Rendezvous Values
- Repartition
- Repdigit