I'm an engineering major, and my school has a lab that works on control theory. I think I would like to work on this in grad school, but I don't know if I have the background to look into it yet? I found a free textbook on the subject from Rutgers: http://www.math.rutgers.edu/~sontag/FTP_DIR/sontag_mathematical_control_theory_springer98.pdf" [Broken] I've only studied Calc I-III thus far. Linear Algebra isn't required for my degree, and I only need to take a "Intro to Diff. EQs" class, which I'm guessing is pretty lightweight. What am I going to have to study to be able to understand material in a textbook like this? - Diff Equations? - Linear Algebra? - Real/Complex/Functional Analysis? - Abstract Algebra? - Geometry/Topology? The textbook preface says that only linear algebra and diff equations are required, but I'm skeptical.