What math topics should I focus on as an undergraduate student ?
Ofcourse you should know Basic Calculus and Differential Equations stuff as this is only a start. But I would like to emphasize on two topics
1. Probability Theory
2. Linear Algebra
These will help you a lot on the applied side and when solving engineering problems. Especially master your probability theory (random variables, stochastic processes) as they are the keys to
really understand many problems.