Arg max

In mathematics, arg max (or argmax) stands for the argument of the maximum, that is to say, the value of the given argument for which the value of the given expression attains its maximum value. This is well-defined only if the maximum is reached at a single value. Thus

<math>x_0 = \arg \max_x f(x)<math>

holds if and only if x₀ is the unique value of x for which f(x) is maximized.

arg min (or argmin) is defined analogously.