Well, dynamical systems are everywhere, and if one studies engineering/physics/maths... They will be covered.

Both Bode and Nyquist plots are used to determine whether a system is stable, and in that case, how robust it can be, at various frequencies of the input variable.

There is a LOT of math (differential equations, matrices, eigenvalues, complex numbers, Laplace transforms...) behind these, it's quite interesting.