23.3.
:
f(x)=0 (23.5)
: 1) , .. [a,b] OX, ; 2) .
. .
3-x-ln(x)=0.
3-x=ln(x) y=3-x y=ln(x) (. 23.3). , - , [1,3]. : f(1)=3-1-ln(1)>0, f(3)=3-3-ln(3)<0. , , [1,3], =1, =3.
, (23.5) Mathcad Excel.
, ( ), , .
. . x0=a, f(a) f¢¢(a) x0=b, f(b) f¢¢(b) . :
xn+1=xn─ , n=0,1,2, (23.6)
, | xn+1 - xn | <= e, e . .
1. a, b, e.
2. xn1=a,
f(a) ×f¢¢(a)> 0 xn1=b .
3. xn=xn1.
4. xn1=xn─
5. | xn1 - xn | > e, 3. .
6. xn1.
f(x) (23.5), f¢(x) f¢¢(x) - , .
( ). [a,b] . , f(x) . . , 2e.
.
1. a, b, e.
2. .
3. f(x)=0, 6, .
4. f(x)×f(a)<=0 b=x, a=x.
5. |a-b|>2e, 2, .
6. x.