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

$\dfrac{106}{3} \ ft/second$ or, $35.333 \ ft/second$
The general formula for the average rate of change of distance (S) from $t=3 \ seconds$ to $t=6 \ seconds$ is: $\dfrac{f(y)-f(x)}{y-x}$ Here, we have: $\dfrac{\triangle s}{\triangle t}=\dfrac{S(6)-S(3)}{6-3}$ or, $=\dfrac{137-31}{3}$ or, $=\dfrac{106}{3}$ or, $=35.333 \ ft/second$