, . . . . . . . .
1.3
.
. .
1.4 .
. . . . . . . .
2. .
2.1 . .
. . . . . .
2.2 ,
. . - .
2.3 .
. . .
3.
[2] 4- 8,10 [4] 57- 64
3.
1. : , - = 3
: .. = d /dx, dy/dx y = , dy = ( + ) dx,
(2+1): dy/y(y2+) = dx/x 1/(2 + 1) =
(2 + 1 2)/ (2 + 1) = (2 + 1)/ ((2 + 1)) 2 ((2 + 1)) = 1/-/(2 + 1),
2. 2sinydx + (x2+3)cosydy=0
, =1
: (2+3) siny
In(x3+3)+In(siny)=Inc,
In(x2+3) ∙(siny)=Inc,
(x2+3) ∙ (siny)=c
siny= -
1=
: sin y= -
3.
1.
=uv, =
|