Appendix B

W. Bolton

As will be evident from the models discussed earlier, many systems have input-output relationships which have to be described by differential equations. A *differential equation* is an equation involving derivatives of a function, i.e., terms such as *dy*/*dt* and *d*^{2}*y*/*dt*^{2}. Thus:

is a differential equation. The term *ordinary differential equation* is used when there are only derivatives of one variable, e.g., we only have terms such as *dy*/*dt* and *d*^{2}*y*/*dt*^{2} and not additionally *dx*/*dt* or *dx*^{2}/*dt*^{2}. The *order* of a differential equation is equal to the order of the highest derivative that appears in the equation. ...

Start Free Trial

No credit card required