- Affine space
can be embedded in
by
- Affine points can be recovered from projective points with
by
- A projective point with
corresponds to a
**point at infinity**. - The ray
can be viewed as an additional
**ideal point**as recedes to infinity in a certain direction. For example, in ,

**It is important to note that these are affine concepts**.

Subhashis Banerjee 2008-01-20