Vectors in space

### 27.4.4 Vectors in space

See Section 26.6.4 for vectors in the plane.

The vector command returns and draws vectors. It can take its arguments in two different ways.

1. The coordinates of the vector.
   - vector takes L, a list of the coordinates of the vector.
   - vector(L) returns and draws the vector with the given coordinates, starting from the origin.
2. Two points or a point and a vector.
   - vector takes two arguments:
     - P, a point.
     - Q, a point or a vector.
   - vector(P,Q) returns and draws the corresponding vector. If the arguments are two points, the vector goes from P to Q. If the arguments are a point and a vector, then the vector starts at P.

#### Examples

vector([1,2,3])

vector(point(-1,0,0),point(0,1,2))

or:

vector([-1,0,0],[0,1,2])

V:=vector([-1,0,0],[0,1,2]); vector(point(-1,2,0),V)