We recommend following Youtube Videos by Steven L. Brunton, professor of the University of Washington in Seattle, nicknamed Eigensteve, to brush up your math skills:

• Differential Equations and Dynamical Systems
  Topics covered include: Ordinary Differential Equations, Charasteristic Equation, Higher Order ODEs, From a Higher Order ODE to a System of First Order ODEs in Matrix Form, Meaning of Eigenvalues and Eigenvectors in an ODE system, Jordan Canonical Forms, Linearizing non Linears DEs, Jacobian Matrix, Phase Portrait of Nonlinear DEs using Taylor expansion around center fixed points, how to choose DeltaT in computer simulations, Discrete Riemann Integration, Runge Kutta Integration for DEs. 49 videos, ~25 hours
• Complex Analysis
  Euler's Formula, Analytic Functions of a Complex Variable, the Complex Logarithm Log(z), Cauchy-Riemann conditions solve Laplace Equations, Integrals in the Complex Plane around Singularities. 13 videos, ~7 hours
• Vector Calculus and Partial Differential Equations
  Div, Grad, Curl as building blocks to solve PDEs, Gauss Divergence Theorem, Continuity Equation, a PDE for mass conservation, Stokes Theorem and Green's Theorem, Solving for the Heat and Wave Equation. 23 videos, ~8 hours
• Reinforcement Learning
  Discrepancy Modeling with Physics Informed Machine Learning, Neural Networks meet Control Theory, Q-Learning. 9 videos, ~4 hours