25.)
, :
1. ( BD). , .
2. .
h e .
2 : n 2n . e, . , .
,
:
1) :
, .
2)
3) .
,
.
- 4 .
- 4- - , 4 : , .
y = f(x,y) :
,
i = 0, 1, ., n-1 - ;
xi = a + i×h - ;
0 = (0) - .
d = (h5).
- 4- .
26.)
.
x - ,, n .
yi - , ,
yi|x=x0 =yi0 - .
yi(x), , .
:
yij+1=yij+hfi(xi,y1j y2j..ynj)
j - .
xj+1=xj+h
.
ki1=h*fi(xj,y1j..ynj)
ki1=h*fi(xj+h,y1j+ki1..ynj+ki2)
yij+1=yij+(ki1+ki2)/2
xj+1=xj+h
1- :
y′ = f(x, y, z)
z′ = g(x, y, z)
y(x0) = y0 , z(x0) = z0 .
:
yi+1 = yi +∆yi ,
zi+1 = zi + ∆zi ,
∆ yi ∆ zi :
∆yi = hf(xi , yi , zi)
∆zi = hg(xi , yi , zi)
- :
k1 = hf(xi , yi , zi),
|
|
l1 = hg(xi , yi , zi),
k2 = hf(xi+h, yi+k1 , zi+l1),
l2 = hg(xi+h, yi+k1 , zi+l1).
.
27.)
.
, :
1. . , () .
2. , . , .
[ a, b ] , :
.
:
1) f (xi) = yi xi Î[ a, b ].
2) P (x), (xi, yi), :
:
, - , Ai , R , .( )
, OX, f(x), x=a x=b
[a, b] n . , x0, x1,, xn .
, , , i- :
,
n :
Si .
28.) .
, :
- . , () .
2. , . , .
[ a, b ] , :
.
:
1) f (xi) = yi xi Î[ a, b ].
2) P (x), (xi, yi), :
:
, - , Ai , R , .( )
.
i- ( ) fi. :
|
|
Si .
, .. .
:
Si .
:
,
Si .
:
Si , ( δ1 δ2).
.
.