This document summarizes an exam preparation workshop on the application of partial differentiation presented by Dr. Richard Ng. It provides the answers to two sample exam questions, finding the critical points and determining whether they are maxima or minima for multivariate functions. For the first question, the critical point is found to be (7/3, 8/3) which is a minimum. For the second question, the critical point is (-4, 2) which is also determined to be a minimum using the second derivative test.