- instantaneous rate of change
- Down and Out in Paris and London (gutenberg.net.au)
THE rue du Coq d’Or, Paris, seven in the morning. A succession of furious, choking yells from the street. Madame Monce, who kept the little hotel opposite mine, had come out on to the pavement to address a lodger on the third floor. Her bare feet were stuck into sabots and her grey hair was streaming down.
- Derivative (Wikipedia)
In mathematics, the derivative shows the sensitivity of change of a function’s output with respect to the input. Derivatives are a fundamental tool of calculus. For example, the derivative of the position of a moving object with respect to time is the object’s velocity: this measures how quickly the position of the object changes when time advances.