Chapter 15, Problem 14P

Develop an M-file that is express ly designed to locate a maximum with the golden-section search algorithm. In other words, set it up so that it directly finds the maximum rather than finding the minimum of $-f\left(x\right)$. Test your program with the same problem as Example 13.1. The function should have the following features:

• Iterate until the relative error falls below a stopping criterion or exceeds a maximum number of iterations.

• Return both the optimal x and $f\left(x\right)$.