We discussed some variations of Cauchy's theorem, and their uses. We derived Cauchy's Integral Formula, and used it to prove that if a function f is analytic at a point then it has infinitely many derivatives at that point. We also generalized the Integral Formula to give analogous formulas not just for f but each derivative of f. We derived Cauchy's Inequality and used this to derive Liouville's theorem. HW: sections 45,49, 52