More Math Styled with Pure CSS

One thing under examination here is the new CSS border-radius property that may be used to “round” border corners.

From linear algebra:

The companion matrix of a monic polynomial


of degree n with coefficients in a field F is the matrix of the linear map given by “multiplication by t” in the quotient space


with respect to the basis of that space given by the residue classes {1,t,t2,,tn1}. That matrix is