(): .
: 0 x : , . (1)
f (x) , , , : ()( .
() , . x=g(y), . (x - ), y =g(x) . - :
1) , ;
2) ;
3) y=x.
. = f (x) ( ) [ ;b ], [ ; ], = f (a), = f (b) ( ) x=g(y).
g f(x) - : .
[ a,b ] , .
, . ( , ), . : . , f [ a,b ] x=g(y), D(g) =[A;B], E(g) =[ a;b ].
, g [A;B]:
: < Þ 1 < 2. (2)
, , f, . 1 = 2 . , .
. , . ( ), . , . , y0, , . y0.
: , . .n