2.3. Basis of vector and coplanar vectors

Three vectors a, b, c parallel to one plane are called coplanar vectors. If the vectors a, b, c, are not coplanar, then they are called a basis in R ³ . (For a precise definition of the basis, see [1, 3, 6].)

Two vectors a, b parallel to one straight line are called collinear
(designation: ). If vectors are considered on a plane, then non-collinear vectors a, b are also called basis .