. | -3 | .10: 114, 116, 118, 120, 122,124. |
☺ ☻ ☺
1 114: : y =(y′)2+4(y′)3 .
:
a 0. : y =φ(y′).
, :
a 1. y′ = p. : y =φ(p)= p 2+4 p 3.
a 2. : y′ = , dy =φ′(p) dp, : φ′(p)=2 p +12 p 2. x: dx = dp =(2+12 p) dp.
a 3. x: x = +=2 p +6 p 2+.
a 3. : , .
a 4. p → F (x, y, C)=0 . !
: . y=0 .
2 116: : y =(y′ 1) ey′ .
:
a 0. : y =φ(y′).
, :
a 1. y′ = p → : y =φ(p) =(p 1) e p.
a 2. : y′ = , dy =φ′(p) dp, : φ′(p)= pe p. x: dx = dp = e p dp.
a 3. x: x = += e p +.
a 4. : , .
a 5. p → F (x, y, C)=0 . !
: .
3 118: : x = y′ 3 y′ +2 .
:
a 0. : x =φ(y′).
, :
a 1. y′ = p. : x =φ(p)= p 3 p +2.
a 2. : y′ = , dy = pdx, dx =φ′(p) dp, : φ′(p)=3 p 21. y: dy = p φ′(p) dp =(3 p 3 p) dp.
a 3. y: y = += p 4 p 2+= μ (p)+.
a 4. : ,
a 5. p → F (x, y, C)=0 . !
: .
4 120: : x =2 y′ ln y′ .
:
a 0. : x =φ(y′).
, :
a 1. y′ = p. : x =φ(p)=2 p ln p.
a 2. : y′ = , dy = pdx, dx =φ′(p) dp, : φ′(p)=2 . y: dy = p φ′(p) dp =(2 p 1) dp.
a 3. y: y = += p 2 p += μ (p)+.
a 3. : ,
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a 4. p → F (x, y, C)=0 . !
: .
5 122: : y = x , .
:
a 0. : y =φ(y′)∙ x +ψ(y′), φ(y′)= ψ(y′)=0.
, :
a 1. y′ = p → : y =φ(p)∙ x +ψ(p)= x ∙ .
a 2. x : p φ(p)=[ x∙ φ ′ (p)+ψ ′ (p)] .
a 3. : p φ(p)= =0, : p0 =1 p0 =1. p0 ≡φ(p0), : ) p0 =1: y =φ(p0)∙ x +ψ(p0) → y =1∙ x +0= x;
) p0 =1: y =φ(p0)∙ x +ψ(p0) → y =1∙ x +0= .
, , , .
a 4. p φ(p) ≠ 0. x:
x = , x = , = (x +1) .
a 5. p φ(p)≠0. x : x = . : x ∙ =0, = x : → p = C x.
a 6. C: → y = Cx 2+ .
: y = Cx 2+ . : y = x.
6 124: : y =x(y ′)2+(y′)3, .
:
a 0. : y =φ(y′)∙ x +ψ(y′), φ(y′)=(y ′)2 ψ(y′)=(y′)3.
, :
a 1. y′ = p → : y =φ(p)∙ x +ψ(p)= x ∙ p 2+ p 3.
a 2. x : p φ(p)=[ x∙ φ ′ (p)+ψ ′ (p)] . : p p 2=[ x∙ 2 p +3 p ] .
a 3. : p φ(p)= p p 2=0, : p0 =0 p0 =1. p0 ≡φ(p0), : ) p0 =0: y =φ(p0)∙ x +ψ(p0) → y =0∙ x +0=0;
) p0 =1: y =φ(p0)∙ x +ψ(p0) → y =1∙ x +1= +1.
, , , .
a 4. p φ(p)≠0. x : x = . : x = =0, + x = .
, :
a 5. : x = u ∙ v.
a 6. : = =2ln|p1|, : u = , u = .
a 8. v: v = += + = p 2 p 3+.
a 9. x:
x = u ∙ v = ∙ = ∙ + .
: , : x = p + .
a 10. : y = x ∙ p 2+ p 3 x, y p: y = p 2+ .
a 11. : .
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a 12. p → F (x, y, C)=0 . !
: . : y =0; y = x +1.
* * * * * * * * * *
-3 | .10: 115, 117, 119, 121, 123,125, 177. |
1 115: : y = y′ .
:
a 0. : y =φ(y′).
, :
a 1. y′ = p. : y =φ(p)= p .
a 2. : y′ = , dy =φ′(p) dp, : φ′(p)= + = . x: dx = dp =( + ) dp.
a 3. x: x = + +=J1+J2+. : J1= =[: p 2= t ]= =[: = u ]= =ln p ln(1+ ),
J2=2 . : x =2 +ln p ln(1+ )+.
a 3. : .
a 4. p → F (x, y, C)=0 . !
: . y=0 .
2 117: : y = +2 xy′ + x 2.
:
a 0. : y = F (x, y′): .
, :
a 1. y′ = p → : y = p 2+2 xp + x 2.
a 2. , p x, y x, y′ = p: p =(p +2 x) +2 p +2 x, : (p +2 x)( +1)=0. (2.1)
a 3. (2.1) :
▪ p = 2 x → dy = 2 xdx → y = x 2+. y = x 2+ , =0. , y = x 2 .
▪ dp = dx → p = x + → dy =(і x)→ y = x . y = x , : y = x + ( 2 x 2).
a 4. , : y = x + ( 2 x 2) . : y = x 2 .
: y = x + ( 2 x 2) . y = x 2 .
3 119: : x = y′ cos y′.
:
a 0. : x =φ(y′).
, :
a 1. y′ = p. : x ==φ(p)= p cos p.
a 2. : y′ = , dy = pdx, dx =φ′(p) dp, : φ′(p)=cos p p sin p. y: dy = p φ′(p) dp = p (cos p p sin p) dp.
a 3. : y = += =J1J2+. J1 : J1= psinp + cosp. J2 , : J2= p 2cosp+2 = p 2cos p +2J1. :
y = p 2cos p psinp cos p +.
a 4. : .
: .
4 121: : x = + .
:
a 0. : x =φ(y, y′). y′ = , : x = x′∙ y + x′2. ! , , , .
:
a 1. y′ = p. : x =φ(y, p)= + , p y (!) x.
a 2. : y′ = , x =φ(y, p) y:
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= 2 → (2+ py) =0.
a 3. :
) =0 → p = → : x = y +2;
) 2+ py =0 → 2 dx + ydy =0 → 4 x + y 2=0 ( !).
: x = y +2 , 4 x + y 2=0 .
5 123: : y =2 xy′ + , .
:
a 0. : y =φ(y′)∙ x +ψ(y′), φ(y′)=2 y′ ψ(y′)= .
, :
a 1. y′ = p → : y =φ(p)∙ x +ψ(p)= 2 xp + .
a 2. x : p φ(p)=[ x∙ φ ′ (p)+ψ ′ (p)] .
a 3. : p φ(p)= p 2 p = p =0, : p0 =0. p0 ≡φ(p0), : y =φ(p0)∙ x +ψ(p0), , ψ(p0) .
a 5. p φ(p)≠0. x : x = . : x = , + x = : .
, :
a 5. : x = u ∙ v.
a 6. : = =2ln|p|, : u = , u = .
a 8. v: v = += 2 + = +.
a 9. x:
x = u ∙ v = ∙ = .
a 10. : y =2 xp + x, y p: y = .
a 11. : .
a 12. p → F (x, y, C)=0 . !
: .
6 125: : y = y ′ x+ y′lny′, .
:
a 0. : y =φ(y′)∙ x +ψ(y′), φ(y′)= y ′ ψ(y′)= y′lny′.
, :
a 1. y′ = p → : y =φ(p)∙ x +ψ(p)= x ∙ p + plnp.
a 2. x : p φ(p)=[ x∙ φ ′ (p)+ψ ′ (p)] . : p p = [ x∙ 1+ln p +1] , p =[ x +ln p +1] .
a 3. : p φ(p)= p =0, : p0 =0. : y =φ(p0)∙ x +ψ(p0), , ψ(p0) .
a 4. p φ(p)≠0. x : x = . : x = =0.
, :
a 5. : x = u ∙ v.
a 6. : = =ln|p|, : u = , u = p.
a 8. v: v = += + = (ln p +2)+.
a 9. x:
x = u ∙ v = p ∙ =Cplnp2.
a 10. : y = x ∙ p + plnp x, y p: y = C p 2p.
a 11. : .
a 12. p → F (x, y, C)=0 . !
: .
5 177: , (3,1), , , .
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:
1 19 : =(0, y y ′ ) ND =( yy ′,0).
: . : =(0, y y ′ ), | |=| y y ′ |, | ND |=| yy ′|, : | |=| ND |.
:
▪ -1: y y ′ = yy ′; (1)
▪ -2: y y ′ = yy ′. (2)
-1.
a 0. (1) : y = ∙ . : y =φ(y′)∙ x +ψ(y′), φ(y′)= ψ(y′)=0.
, :
a 1. y′ = p → : y =φ(p)∙ x +ψ(p)= x ∙ .
a 2. x : p φ(p)=[ x∙ φ ′ (p)+ψ ′ (p)] .
a 3. : p φ(p)= =0, : p0 =0. p0 ≡φ(p0), : y =φ(p0)∙ x +ψ(p0) → y = 0∙ x +0= 0. , , .
a 4. p φ(p) ≠ 0. x: x = , x ∙ =0, = x .
a 5. ( : , : . !): = = ln , :
ln = +C.
a 6. : y = x ∙ , = +1. ln y = 1+C, =Cln y .
a 7. , : =3ln y , C=3.
-2.
a 0. (1) : y = ∙ . : y =φ(y′)∙ x +ψ(y′), φ(y′)= ψ(y′)=0.
, :
a 1. y′ = p → : y =φ(p)∙ x +ψ(p)= x ∙ .
a 2. x : p φ(p)=[ x∙ φ ′ (p)+ψ ′ (p)] .
a 3. : p φ(p)= =0, : p0 =0. p0 ≡φ(p0), : y =φ(p0)∙ x +ψ(p0) → y = 0∙ x +0= 0. , , .
a 4. p φ(p) ≠ 0. x: x = , + x ∙ =0, = x .
a 5. ( : , : . !): = = ln +C, : :
ln = +C.
a 6. : y = x ∙ , = 1. ln y = +1+C, =C+ln y .
a 7. , : =3+ln y , C=3.
: 2 ; , .
: =3ln y . : y = 0.
☻
:
1. 1- , ?
2. , .
3. y=φ(y′)?
4. x=φ(y′)?
5. F (y, y′)=0?
6. F (x, y′)=0?
7. ?
8. .
9. .
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