These exercises will be presented as a quation of application, with concrete parameters. It's your job to transform this question into a mathematical function, and then find the extremum of this function in the interval which you have to determine.

For the numerical computations involved in the exercises, you may make use
of the online calculators on this server. You can copy the solution given by
the calculator to the page of the exercise; the required precision for the
solution is usually around
10^{-4}.