A differential equation is given along with the field or problem area in which it arises. Classify it as an ordinary differential equation$($ODE$)$ or a partial differential equation$($PDE$),$ give the$$ order, and indicate the independent and dependent variables. If the equation is an ordinary differential$$ equation, indicate whether the equation is linear or nonlinear.

StartRoot $1$ minus y EndRoot StartFraction d squared y Over dx squared EndFraction plus $2$ x StartFraction dy Over dx EndFraction equals $0$

$($Kidder$\text{'}$s equation, flow of gases through a porous$$ medium$)$;