Hi guys, just embarking on the journey of modeling with differential equations and solving them. I have a more conceptual quesiton. Linear differential equations in my book are defined to be ones where F(t, y, y', y'',...,yn) = 0 is a linear function of the dependent var y and all of its derivatives. Does this mean that if in the equation we have say "...ty" it is still linear? If yes, then how does this translate to linear algebra where in a system of linear equations the functions have to be linear for all the variables, including the "free" ones?