A model for the average price of a pound of white sugar in a certain country from August 1993 to August 2003 is given by the function...

Hello!

Of course all points where maximum and minimum are reached are the endpoints, `t=0` and `t=10,` and the points where `S'(t)=0.` But even the derivative has degree `4` and such an equation cannot be solved by hand.

But with the help of computers we can do this easily. I'll use desmos.com, it is free and shows maximums and minimums (mark the graph line by mouse).

Look at the picture attached and the link with...

Hello!

Of course all points where maximum and minimum are reached are the endpoints, `t=0` and `t=10,` and the points where `S'(t)=0.` But even the derivative has degree `4` and such an equation cannot be solved by hand.

But with the help of computers we can do this easily. I'll use desmos.com, it is free and shows maximums and minimums (mark the graph line by mouse).

Look at the picture attached and the link with the graph, https://www.desmos.com/calculator/setjq3krbu

It shows that the global minimum is at `t_1=0.878` and the global maximum is at `t_2=4.523.`

These are the times when sugar was cheapest and most expensive. You can estimate the corresponding dates using computer calendar.