1.
2.
3. -
4.
5. ̳
` , . ` , , , .
. ֳ , , , ` .
` .
=f(x,y) (1) (0)=0 (2). , =(), ` (1) (2). , , , ` , .
, D 0, (0;0), f(x,y) , 0 =(), ` (1) (2) ( ).
:
) , =f(x,y,y) (3), (0)=0, (x0)=y0. =(), ` (3) (4).
) ,
(5) x(t0)=x0, y(t0)=y0. (6)
=(t), y=y(t), ` (5) (6);
) ,
(7)
.
. =f(x,y) (1) (0)=0 (2) [x0;x0+a].
(1), (2) [x0;x0+a] n , h= . h ( ). =() 0, 1=0+h, x2=x1+h, , xn=xn-1+h=x0+a.
` . , [x;x+h] =() (1) (;()). , [x0;x1] 0(0;0) , (x0)=f(x0,y0), -0=f(x0,y0)(x-x0). , 1, =1. ϳ =1 , 1=0+f(0,0)(-0)=y0+f(0,0)h. 1 1. [x1;x2]. , , 1(1;1), (x1)=f(x1,y1), -1=f(x1,y1)(x-x1), 2 2(2;2), 2=1+f(x1,y1)(x2-x1)=y1+f(x1,y1)h. 2 2.
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, [xn-1;xn=x0+a] n=yn-1+f(xn-1,yn-1)h n(xn;yn). n n.
ǒ 0,1,...,n, , . . г - , (1), (2) [x0;x0+a].
- . ( =f(x,y) (1) (0)=0 (2). , =(), ` (1) (2)) , [; x+h] y=y(x) (1) , (;=()). , , .
[x0;x0+a] n x0, x1,...,, +1,..., n=x0+a(xk+1-xk= =h) 0,..., x0,..., x. [xk; xk+1] +1. 1=f(xk;yk) Mk(xk;yk), y-yk= 1(x-xk) =+ , N . N : 2=f 2: y-yk= 2(x-xk) =+ . N . N : 3=f 3: y-yk= 3 (x-xk) =+h. (+h,yk+ 3h). : 4=f . , , =1/6( 1+2 2+2 3+ 4) Mk y-yk= (x-xk) =+h Mk+1(xk+1;yk+1), yk+1=+ h xk+1=+h.
, - - . - ( ), .
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, . +1, fi+1 fi+1 , -1,-2 +1. :
+1=+ (55*fi-59*fi-1+37fi-2-9fi-3), fi=f(xi,yi).
+1 fi+1=f(xi+1,yi+1) +1:
+1=+ (9*fi+1+19*fi-5fi-1+fi-2). .
̳ . - 0, 1, 2, 3. :
1. 1. +1:
+1=-3+ h(2fi-fi-1+2fi-2), fi=f(xi,yi); (i=3,4,5,)
2. 2. fi+1=f(xi+1;yi+1).
3. 3. +1:
+1=-1+h/3(fi-1+4fi+fi+1), (=3,4,...)
̳ = 1/29|yi-|