Terminology Definition(DE) Differential equations:equations containing an unknown func- tion and one or more of its derivatives. 4日10y至,1元3000 Ordinary Differential EquationsTerminology Definition (DE) Differential equations: equations containing an unknown function and one or more of its derivatives. Definition (ODE) Ordinary differential equations: differential equations that involve an unknown function of a single independent variable . Example The population function P(t) dP dt = kP Ordinary Differential Equations