"After my one course in linear algebra, I knew eigenvectors and eigenvalues like the back of my head. If your instructor was anything like mine, you recall solv

"After my one course in linear algebra, I knew eigenvectors and eigenvalues like the back of my head. If your instructor was anything like mine, you recall solving problems involving eigendoohickeys, but you never really understood them." -- Jonathan Richard Shewchuk, from An Introduction to the Conjugate Gradient Method Without the Agonizing Pain