, , , ; , , ;
́ . , , . , , .
z =z (x,y), (x,y) D, M0(x0,y0) D. M0 - (. . (1.41) ). :
:
( ), .
z =z (x,y), (x,y) D. M0(x0;y0 D - .
z'x z'y,
"". C0 (.1.4) , "" , . . 0 .
(.1.3):
.
50.=33.
y = f(x) (a; b), .
y = f(x) (a; b), .
, (a; b) (b; c).
52=46
. y = f (x) (a, b). , (x 0, f (x 0)) y = f (x) , f " (x 0) = 0.
. y = f (x) f "(x) x 0 (a, b), , 0, = ( 0, f (x 0)). 0 f "(x) , y = f (x).
53.=46
.
1.
2.