() . .
( 2):
f (x) = 0
f(x) .
f (x) . , f (x) n - (n > 1):
f(x) = n() = an xn + an1 xn-1 + + a1 x + a0
. f(x) , : , , , .
( 3). x* f (x) = 0, f (x) 0, .
. , , , . . :
, ε > 0,
, [a;b], . , . 2 ( 4):
1) , , ;
2) .
, x*: x 0, x 1,..., xn, n ¥ , x*, , . xk, ε x*.
. , .
.