## Precalculus: Concepts Through Functions, A Unit Circle Approach to Trigonometry (3rd Edition)

Let $s(t)$ be the position function of the particle. The velocity of the particle can be defined as the rate of change of the position function and can be written as: $v(t)=\dfrac{d (s(t))}{dt}$. Or, in alternative notation, $v(t)=s'(t)$