Calculate and interpret average and instantaneous rates from a model
Consider the function for the changing quantity shown below
\[V(t)=40 + 4\,t - \frac{1}{4}\,t^{3}\]
V is measured in litres, and t is measured in minutes
\[t\in[0,3]\]
Determine the average change per input-unit on the stated interval
\[t_1=0,\quad t_2=1\]