Originally Posted by

**chiro** Hey GreyWolf.

I don't know about any specific resources that meet that need, but one thing that you can do is discuss the rotation matrix. This will link all the topics together in a nice fashion.

The idea is that you start off in 2D and you want to rotate a point some angle. So you start with a point (x,y) rotate it (x',y') and then construct the matrix to take (x,y) to get (x',y') where (x,y) = x, (x',y') = b and Ax = b where A is a 2x2 matrix.

You can derive this using some basic trig addition laws for sin(a+b) and cos(a+b) which can be proved either geometrically or otherwise. Once you do this you derive your rotation matrix and then introduce matrix multiplication where Ax = b and you can look at the inverse process to get x given b by using x = inv(A)*b, and show that inv(A) simply rotates by the negative of the angle by showing that you get -theta instead of +theta.

That should link up matrices, vectors and trig nicely.