In the last installment I introduced the idea of a ** transformation matrix** — a square matrix that we view as a set of (vertically written) vectors describing a new

*basis*for a transformed space. Points in the original space have the same relationship to the original basis as points in the transformed space have to the transformed basis.

When we left off, I had just introduced the idea of a ** rotation matrix**. Two immediate questions were: How do we create a rotation matrix, and how do we use it. (By extension, how do we create and use

*any*matrix?)

This is where our story resumes…