if any/anything

ε

& gt

0,

Such that all satisfy 0: f(x)

Let's call f(x0) the maximum value of the function f 。

Minimum value:

if any/anything

ε

& gt

0,

Such that all satisfy 0

Let's call f(x0) the minimum value of the function f 。

Maximum: If any x is defined in the domain, f (x)

Minimum value: if any x is defined in the domain, f (x) >; =f(x0), we call f(x0) the minimum value of the function f 。

Extreme value is a local concept, and maximum value is a whole concept.

So the landlord's problem is f (x) = x (x >; There is no non-empty neighborhood at = 1)x= 1 (that is, x= 1 has no domain to the left), so f(x) has no value at x= 1, but is defined by the maximum value, and f(x) is at x =/kloc-0.