Introduction: The rate of production can be important information. The rate of production is the derivative of the production function.

Definition: For a production function $P(t)$ the rate of production is given by $P'(t)$.

Example: For a production function $P(t)=10t$, with $t$ in hours. The rate of production is $P'(t)=10$ for every $t$. Hence, 10 products are produced per hour.