Terminology Definition (DE) Differential equations:equations containing an unknown func- tion and one or more of its derivatives. Definition (ODE) Ordinary differential equations:differential equations that in- volve an unknown function of a single independent variable. Example The population function P(t) dP =kP dr 4口14①y至元2000 Peipei Shang School of Mathematical Sciences shang@tongji.edu.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 Peipei Shang School of Mathematical Sciences shang@tongji.edu.cn Ordinary Differential Equations