So my course shows me three differential equations:
The first one is not a linear ordinary differential equation (ODE) apparently, the other two are.
Unfortunately, they don't show a clear way how to find out if an ODE is linear or not. So how we can find out if an ODE is linear?
For the second one, I thought I bring it into standard form somehow:
If we say we let and , then we could say:
And so on, to simplify until we reach standard form of a linear ODE (or not).
Is that the way to go? Or is there some other way to check if a ODE is linear?