I've completed my under graduation in economics where I used micro books like Nicholson and Snyder's Microeconomic Theory and Hal Varian's Intermediate Microeconomics. I am comfortable with topics like Differentiation, Integration, Matrices, Determinants, Functions, Theory of Equations, Limits, Continuity, Sequence & Series, LPP, First order and second order ODE and other basic stuff taught at undergrad level in Ancillary course. For the Post Graduate course in Economics I'll be required to study from Whinston and Green's Microeconomic Theory. After flipping through the pages of it I realized that it contains a lot of mathematical symbols that I don't understand. So please suggest essential topics from mathematics(along with references suitable for self study) which will enable me to understand this book.