The absolute minimum
, or global minimum
, of a is the least in its whole .
The absolute maximum, or global maximum, of a function is defined in a similar way. It is the greatest output of the function in its whole domain.
The absolute maximum of a function is also a , and the absolute minimum is also a . If a function indefinitely, it does not have an absolute maximum. Likewise, if a function indefinitely, it does not have an absolute minimum. The function might still have relative extrema.