Abstract Algebra: Let G = GL(2,R) be the set of real 2x2 invertible matrices. In this first part, we show that G is a group. Using the identity det(AB)=det(A)det(B), we give an indication of how to extend to nxn invertible matrices.
Includes course on Group Theory (problems and solutions at website) and Ring Theory, and Field Theory. For Prerequisites on proofs and sets, see the Math Major Basics course.