Advanced Linear Algebra - Steven Roman - Google Books

http://books.google.de/books?id=bSyQr-wUys8C&pg=PA208&dq=triangle+inequality&as_brr=3

This is a graduate textbook covering an especially broad range of topics. The first part of the book contains a careful but rapid discussion of the basics of linear algebra, including vector spaces, linear transformations, quotient spaces, and isomorphism…