1) f(x) , f(x + Dx) > f(x) Dx>0 f(x + Dx) < f(x) D<0,
:
2) f¢(x)>0 1 2, [a, b], x1<x2.
: f(x2) f(x1) = f¢(e)(x2 x1), x1 < e < x2
f¢(e)>0, , f(x2) f(x1) >0, .. f(x) .
.
, f(x) [a, b], f¢(x)£0 . f¢(x)<0 (a, b), f(x) [a, b].
, , f(x) [a, b] (a, b).
:
y y
j j j j
x x
.
. f(x) 1 , , 1. f(x) 2 , f(x2 +Dx) > f(x2) D (D ).
, , , . .