The author is spot on. Linear systems show up everywhere from EE to controls. I've never ever ever had to use a Wronskian, ode with non constant coefficients. S

The author is spot on. Linear systems show up everywhere from EE to controls. I've never ever ever had to use a Wronskian, ode with non constant coefficients. Separation of variables is also a fundamental. The only thing I disagree with is what he says about Bessel functions, it's nice to have some exposure to them.