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. 4日1日，4元卡2000 Peipei Shang School of Mathematical Sciences shang tongji.edu.Ordinary Differential EquationsTerminology 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 dt = kP Peipei Shang School of Mathematical Sciences shang@tongji.edu.cn Ordinary Differential Equations