Chapter 4.3, Problem 143E

For the following exercises, consider the production of gold during the California gold rush (1848-1888). The production of gold can be modeled by $G\left(t\right)=\frac{\left(25t\right)}{\left(t^2+16\right)}$ , where t is the number of years since the rush began $\left(0\le t\le 40\right)$ and G is ounces of gold produced (in millions). A summary of the data is shown in the following figure.

143. Find when the minimum (local and global) gold production occurred. What was the amount of gold produced during this minimum?