In this appendix, we use vectors and points as building blocks for more complicated geometry. These topics are used in the book, but not as frequently as vectors, matrices, and transformations; hence, we have put them in an appendix rather than in the main text.
A line can be described by a point p0 on the line and a vector u that aims parallel to the line (see Figure C.1). The vector line equation is:
By plugging in different values for t (t can be any real number) we obtain different points on the line.