f (x) [ a, b ] , f ()* f (b)<0, , , . , f ¢ (x) (a, b).
. x 4 - x 3 - 2 x 2 +3 x 3 = 0
f (x), x :
a) ( ) ;
b) ( ).
: f ¢ (x) = 4 x 3 - 3 x 2 - 4 x + 3
: x = -1, x = 1, x =3/4
, , .
, .
x | - ¥ | - 1 | 3/4 | 1 | + ¥ |
f (x) | + | - | - | - | + |
, , , :
x 1 Î (- ¥, -1), x 2 Î (1, + ¥).
, :
x | - 2 | - 1 | 1 | 2 |
f (x) | + | - | - | + |
, x 1 Î (- 2; -1), x 2 Î (1; 2).
, x 4 - x 3 - 2 x 2 +3 x 3= 0
1, 1 f (x), , .
, .
.
:
MS Excel . , ( Excel ).
1
1. [ a; b ] h k.
:
x | k | f(x) | y(x) | |
2. f (x) y (x).
a | b | h | k | f(x) | |
1 | 1 | 1,5 | 0,05 | 5 | sin(x) - 1/x |
2 | -1 | 0 | 0,1 | 4 | cos(x) - 1/(x+2) |
3 | 1 | 1,2 | 0,02 | 3 | 4x2 - cos(x) 4 |
4 | 0 | 1 | 0,1 | 2 | cos(x) + 1/(x-2) |
5 | -1 | 0 | 0,1 | 9 | ex + 2sin(x) |
6 | -1 | 0 | 0,1 | 7 | x + 1/(x2+1) |
7 | -1 | 0 | 0,1 | 8 | ex + x |
8 | -2 | -1 | 0,1 | 6 | cos(x)-1/(x-2) |
9 | 1 | 2 | 0,1 | 4 | e -x - ln(x) |
10 | 0 | 1 | 0,1 | 7 | e -x - x |
11 | 0 | 1 | 0,1 | 3 | cos(x) - x2 |
12 | -2 | 0 | 0,2 | 4 | x3 - x2 + 3 |
2
|
|
- f (x)=0, x.
- :
, ( ) .
3. f (x) .
f (x)=0 | |
1 | x 3 - 3 x 2 - 4 x + 1=0 |
2 | x 3 21 x + 7=0 |
3 | 10 x = e - x |
4 | 2 x 3 + 2 x -1=0 |
5 | x 3 - 3 x 1=0 |
6 | x3 - 3x2 +1 = 0 |
7 | x3 +6x2 + 9x+ 1= 0 |
8 | e-x = 2 x2 |
9 | x3 - 12x + 5=0 |
10 | x3 - 2x +4=0 |
11 | x3 + x2 + 2 = 0 |
12 | x3 - x2 2 = 0 |
3
- Ax = b A -1 A -1 * b.
- A x b.
b | ||
1 | ||
2 | ||
3 | ||
4 | ||
5 | ||
6 | ||
7 | ||
8 | ||
9 | ||
10 | ||
11 | ||
1 2 |
4
2. :
S = V 0 (1 + P) N , V 0 - ( ), N ( ) P.
3. :