Here you can find my teaching slides that I created and used to go through the required maths material an economist should know before starting their journey in a postgraduate degree. The material starts from the very basics of a line and segment definition and goes all the way to integration and Lagrange maximisation with geometrical interpretation.
Lecture 1: Basics of Linear Functions
Lecture 2: Advanced Functions and System of Equations
Lecture 3: Derivatives and Optimization Techniques
Lecture 4: Expectations & Integration