Documentation

## Maximizing an Objective

All solvers attempt to minimize an objective function. If you have a maximization problem, that is, a problem of the form

`$\underset{x}{\mathrm{max}}f\left(x\right),$`

then define g(x) = –f(x), and minimize g.

For example, to find the maximum of tan(cos(x)) near x = 5, evaluate:

```[x fval] = fminunc(@(x)-tan(cos(x)),5) Local minimum found. Optimization completed because the size of the gradient is less than the default value of the function tolerance. x = 6.2832 fval = -1.5574```
The maximum is 1.5574 (the negative of the reported `fval`), and occurs at x = 6.2832. This answer is correct since, to five digits, the maximum is tan(1) = 1.5574, which occurs at x = 2π = 6.2832.