Элементы вариационного исчисления. Молчанова Л.А. - 9 стр.

UptoLike

Составители: 

Рубрика: 

J[y] =
2
R
0
(y
02
+ 2yy
0
16y
2
)dx; y(0) = 0; y(2) = 0.
J[y] =
2
R
0
(xy
0
+ y
02
)dx; y(0) = 1; y(2) = 0.
J[y] =
1
R
1
1+y
2
y
02
dx; y(1) = 2; y(1) = 3.
J[y] =
1
R
1
(y
2
+ y
02
2y sin x)dx; y(1) = 2; y(1) = 3.
J[y] =
1
R
1
(16y
2
y
00
2
+ x
2
)dx; y(1) = 2; y(1) = 3.
J[y] =
1
R
1
y
02
x
3
dx; y(1) = 2; y(1) = 3.
J[y] =
1
R
0
(y
2
+ y
02
+ 2ye
x
)dx; y(0) = 1/3; y(1) = e
2
/3.
J[y] =
1
R
1
(y
2
y
02
2y sin x)dx; y(1) = 2; y(1) = 3.
J[y, z]=
π/ 2
R
0
(y
02
+ z
02
+2yz)dx;
½
y(0)=1; y(π/2) = 1;
z(0)=0; z(π/2) = 1;
J[y, z]=
R
2
0
(2y
0
z
0
+ y
2
z
2
+2ze
x
)dx;
½
y(0)=1; y(2) = 1;
z(0)= 2; z(2) = 1;
J[y, z]=
R
2
0
(2y
0
z
0
y
2
+ z
2
+2y sin x)dx;
½
y(0)=1; y(2) = 1;
z(0)= 2; z(2) = 1;
J[y, z]=
R
1
1
((y + z)
2
y
02
z
02
+2xz)dx;
½
y(1)=2; y(1) = 0;
z(1)=0; z(1) = 2;
J[y, z]=
R
2
0
((y z)
2
+ y
02
z
02
+2z cos x)dx;
½
y(0)=0; y(1) = 1;
z(0)=1; z(1) = 0;
J[y, z]=
R
2
0
(y
2
+4yz+z
2
y
02
z
02
+ze
3x
)dx;
½
y(0)=1; y(2) = 1;
z(0)= 2; z(2) = 1.
J[y, z]=
R
2
2
(2y
0
z
0
+ y
2
+ z
2
+2ye
x
)dx;
½
y(2)=1; y(2) = 3;
z(2)= 2; z(2) = 1;
J[y, z]=
R
2
2
(y
2
+ z
2
2y
0
z
0
+2ze
x
)dx;
½
y(2)=0; y(2) = 3;
z(2)=2; z(2) = 1;
              R2
    12. J[y] = (y 02 + 2yy 0 − 16y 2 )dx; y(0) = 0; y(2) = 0.
                  0
                  R2
    13. J[y] = (xy 0 + y 02 )dx; y(0) = 1; y(2) = 0.
                  0
                  R1   1+y 2
    14. J[y] =          y 02 dx;   y(−1) = 2; y(1) = 3.
                  −1
                  R1
    15. J[y] =         (y 2 + y 02 − 2y sin x)dx; y(−1) = 2; y(1) = 3.
                  −1
                  R1                    2
    16. J[y] =         (16y 2 − y 00 + x2 )dx; y(−1) = 2; y(1) = 3.
                  −1
                  R1   y 02
    18. J[y] =         x3 dx;   y(−1) = 2; y(1) = 3.
                  −1
                  R1
    19. J[y] = (y 2 + y 02 + 2yex )dx; y(0) = 1/3; y(1) = e2 /3.
                  0
                  R1
    20. J[y] =         (y 2 − y 02 − 2y sin x)dx; y(−1) = 2; y(1) = 3.
                  −1



2. Äëÿ ñëåäóþùèõ ôóíêöèîíàëîâ íàéòè ýêñòðåìàëè è ïîñòðîèòü èõ ãðà-
    ôèêè:
                  π/2                        ½
                  R       02       02         y(0)=1; y(π/2) = 1;
    1. J[y, z]=        (y + z +2yz)dx;
                                              z(0)=0; z(π/2) = −1;
                0                                 ½
               R2 0 0          2     2      x        y(0)=1;      y(2) = −1;
    2. J[y, z]= 0 (2y z + y − z +2ze )dx;
                                                     z(0)=
                                                     ½      − 2;  z(2) = 1;
               R2 0 0                                   y(0)=1;      y(2) = −1;
    3. J[y, z]= 0 (2y z − y 2 + z 2 +2y sin x)dx;
                                                        z(0)= − 2; z(2) = 1;
                                                       ½
               R1                                         y(−1)=2; y(1) = 0;
    4. J[y, z]= −1 ((y + z)2 − y 02 − z 02 +2xz)dx;
                                                          z(−1)=0; z(1) = 2;
                                                          ½
               R2                                            y(0)=0; y(1) = 1;
    5. J[y, z]= 0 ((y − z)2 + y 02 − z 02 +2z cos x)dx;
                                                             z(0)=1; z(1) = 0;
                                                        ½
               R2                                          y(0)=1;     y(2) = −1;
    6. J[y, z]= 0 (y 2 +4yz+z 2 −y 02 −z 02 +ze3x )dx;
                                                           z(0)= − 2; z(2) = 1.
                                                     ½
               R2                                       y(−2)=1;      y(2) = 3;
    7. J[y, z]= −2 (2y 0 z 0 + y 2 + z 2 +2ye−x )dx;
                                                        z(−2)= − 2; z(2) = 1;
                                                     ½
               R2                                       y(−2)=0; y(2) = 3;
    8. J[y, z]= −2 (y 2 + z 2 − 2y 0 z 0 +2ze−x )dx;
                                                        z(−2)=2; z(2) = 1;

                                             9