Mathematics for Economists

This is the math toolkit you'll actually use in upper-level economics: optimization in several variables, the linear algebra behind it, and the dynamics that show up once time enters the picture. You'll spend the semester setting up and solving Lagrangians, working through Hessian conditions, manipulating matrices, and analyzing difference equations on problem sets, with a quiz and two written exams checking that you can execute the techniques cleanly. Coming after single-variable calculus, it's the prerequisite that makes intermediate micro, macro, and econometrics tractable rather than mysterious — most of what looks like "theory" later is really just these methods applied.