1. The problem statement, all variables and given/known data The assignment is to find a matrix, A, that multiplied by a matrix that represents a rectangle will reflect that rectangle about a line through the origin that is at and beta with the x axis. This is all in homogenous coordinates. 2. Relevant equations Elementary vectors: e1 is <1,0, ... 0> e2 is <0,1,0 ...> etc. No others. 3. The attempt at a solution I thought that the matrix might be: (I hope this formats correctly) cos(2B) sin(2B) 0 sin(2B) -cos(2B) 0 0 0 1 But when I use this in Matlab, it seems to rotate the rectangle represented by my first matrix in 3 dimensions, rather than reflect it in two dimensions. So right now I am left trying to remake the matrix. I am trying to figure out the transformation applied to the elementary vectors. When the elementary vector e1 is reflected, that gives me the transformation vector <cos2B,sin2B> but I am having a lot of trouble figuring out the same vector when e2 is reflected. Any ideas? Thank you.