ДКР№5
.pdf8
1 z f x, y x2 2x y2 8 .
.
.
2 d2u |
1 |
, |
1 |
: u 7x sin 6x 3y . |
|
|
|||
2 |
2 |
|
3z f x, y ,
3x2 y2 3z2 8xyz.
|
f x, y, z 16x2y2z2 x2 xz 10x y2 6y 3z 30 A 3, 3, 4 |
|
a 3, 6, 6 . |
5 |
|
|
f x, y 5x2 40x 3y3 27y2 72y 133 . |
6 |
|
|
f x, y 4x2 24x y2 8y 42 2x y 10 0. |
7 |
|
|
f x, y xy x y 3 D x, y | x y 6, x 0, y 0 . |
8
2%,
4% 6%.
2 105 ., 64 106
4 1012 .
,
K0 2 106, L0 4 102.
k KL
MRSLK
MRSLK
k KL .
10
9
1 z f x, y x2 2x y2 6y 1 .
.
.
2 |
|
|
|
z sin 4y2 4x2 3x 3 . |
|
3 |
|
|
|
z f x, y 3x 7y 5z e 3x 7y 5z. |
4z x, y ln 6x2 3y2 M 1, 2
13 x.
f x, y x2y 16y 24x 6xy 4x2 72 .
6f x, y 3x 4y
x 6 2 y 5 2 4.
f x, y x 2 2 y 5 2 14 ABC A 0, 0 ,
B 6, 0 C 0, 15 .
8
2%,
10% 6%.
3 105 ., 64 109
243 1025 .
,
K0 3 105, L0 4 103.
k KL
MRSLK
MRSLK
k KL .
11
10
1 z f x, y 5x2 20x y 18 .
.
.
2 f x, y 3x4 2xy y2 M 0, 1 .
3
z f x, y 251 x2 19 y2 14 z2 3.
4 f x, y ln x2 7x y2 40
A 7, 4 a 14, 48 .
5
f x, y 4x2 40x 3y3 27y2 80 .
f x, y 6x 16y x2 4y2 4.
f x, y xy x y 9 D x, y | x y 14, x 0, y 0.
8
4%,
20% 12%.
4 103 ., 64 106
1024 1020 .
,
K0 4 104, L0 4 102.
k KL
MRSLK
MRSLK
k KL .
12
11
1 z f x, y |
1 |
. |
|
x2 2x y2 63
.
.
2 |
f x, y 2x2 xy 3y2 M 0, 1 . |
||||||
3 |
|
||||||
|
z f x, y |
1 |
x2 |
1 |
y2 |
1 |
z2 5. |
|
|
16 |
16 |
||||
|
4 |
|
|
|
4 f x, y 4x2 4xy 26x 3y2 7y 46
A 4, 1 a 12, 16 .
f x, y 2x2 12x 5y3 15y2 24 .
f x, y 2 x2 4x y2 6y 12 x y 1 0.
7 f x, y xy x y 9
D x, y | x y 14, x 0, y 0.
8
4%,
8% 12%.
4 105 ., 8 109
16 1010 .
,
K0 4 105, L0 2 103.
k KL
MRSLK
MRSLK
k KL .
13
12
1 z f x, y |
1 |
. |
|
x2 y2 10y 16
.
.
2 |
|
|
|
|
|
||||
|
z arctan |
1 |
y. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
|
|
|
2x |
|
|
|
|
|
|
3 |
|
||||||||
|
z f x, y 4x 4y 4z e 4x 4y 4z. |
|
|
|
|||||
4 |
f x, y ln x2 9x y2 14y 70 A 8, 8 |
||||||||
|
a 14, 48 . |
|
|
|
|||||
5 |
|
|
|
|
|||||
|
f x, y 4x2 24x 4y3 84y2 540y 1060 . |
|
|
|
|||||
6 |
|
|
|
|
|||||
|
f x, y 4x2 16x y2 2y 2x y 3 0. |
|
|||||||
7 |
|
|
|
|
|
|
|
|
|
|
f x, y x 3 2 y 6 2 16 |
|
ABC |
|
A 0, 0 , |
||||
|
B 9, 0 C 0, 18 . |
|
|
|
|
|
8
2%,
8% 4%.
2 105 ., 1 104
16 1020 .
,
K0 2 105, L0 1 102.
k KL
MRSLK
MRSLK
k KL .
14
13
1 z f x, y x2 4x y2 5 .
.
.
2 d2u |
1 |
, |
2 |
: u 2x sin 4y x . |
|
|
|||
3 |
3 |
|
3z f x, y ,
2x2 3y2 4z2 10xyz.
f x, y, z 16x2y2z2 x2 xz 12x y2 6y 4z 41 A 4, 3, 4
a 3, 6, 6 .
5
f x, y 3x2 12x 2y3 18y2 42y 7 .
6
f x, y 4x2 16x y2 10y 36 2x y 5 0.
7
f x, y xy x y 3 D x, y | x y 8, x 0, y 0.
8
5%,
15% 15%.
5 104 ., 27 106
125 1015 .
,
K0 5 105, L0 3 102.
k KL
MRSLK
MRSLK
k KL .
15
14
1 z f x, y x2 12x y2 12y 56 .
.
.
2 |
|
|
|
z sin 5y2 x2 x 3 . |
|
3 |
|
|
|
z f x, y 3x 4y 7z e 3x 4y 7z. |
4z x, y ln 5x2 y2 M 1, 2
34 x.
f x, y x2y 7y 18x 6xy 3x2 24 .
6f x, y 12x 64y 233
x 2 2 16 y 4 2 16.
f x, y x 2 2 y 6 2 16 ABC A 0, 0 ,
B 6, 0 C 0, 18 .
8
3%,
6% 12%.
5 103 ., 16 1012
25 108 .
,
K0 5 104, L0 2 103.
k KL
MRSLK
MRSLK
k KL .
16
15
1 z f x, y 4x2 40x y 96 .
.
.
2 |
f x, y 4x4 xy3 y4 M 0, 1 . |
|||||
3 |
|
|||||
|
z f x, y |
1 |
x2 y2 |
|
1 |
z2 6. |
|
|
25 |
||||
|
9 |
|
|
|||
4 |
f x, y ln x2 3x y2 2y 15 |
|||||
|
A 5, 1 a 14, 48 . |
|||||
5 |
|
|||||
|
f x, y 2x2 16x 3y3 36y2 24 . |
|
|
|
||
6 |
|
|||||
|
f x, y 12x 64y x2 16y2 256. |
|||||
7 |
|
|||||
|
f x, y xy x y 3 D |
x, y | x y 6, x 0, y 0 . |
8
5%,
10% 15%.
4 105 ., 1 106
16 1012 .
,
K0 4 106, L0 1 102.
k KL
MRSLK
MRSLK
k KL .
17
16
1 z f x, y |
1 |
. |
|
x2 8x y2 33
.
.
2 |
|
|
|
f x, y 3x2 2xy2 2y3 |
|||||
|
M 0, 1 . |
|
|
|
|
|
|
|
|
3 |
|
||||||||
|
z f x, y |
1 |
x2 |
1 |
y2 |
|
1 |
z2 5. |
|
|
|
|
|
||||||
|
|
25 |
25 |
|
16 |
|
|||
4 |
f x, y 3x2 5xy 7x 2y2 5y 1 |
||||||||
|
A 2, 3 a 6, 8 . |
||||||||
5 |
|
||||||||
|
f x, y 5x2 40x 4y3 24y2 100 . |
|
|
|
|||||
6 |
|
||||||||
|
f x, y 3 x2 8x y2 6y 24 x y 3 0. |
||||||||
7 |
f x, y xy x y 3 |
||||||||
|
D |
x, y | x y 8, x 0, y 0 . |
8
5%,
25% 10%.
4 104 ., 16 104
1024 1020 .
,
K0 4 104, L0 4 102.
k KL
MRSLK
MRSLK
k KL .
18
17
1 z f x, y |
1 |
. |
|
x2 y2 8y
.
.
2 |
|
|
|
|
|
||||
|
z 3 arctan |
3 |
y. |
|
|
|
|
|
|
|
|
|
|
|
|
|
|||
|
|
|
4x |
|
|
|
|
|
|
3 |
|
||||||||
|
z f x, y 4x 8y 4z e 4x 8y 4z. |
|
|
|
|||||
4 |
|
|
f x, y ln x2 x y2 6 |
|
A 2, 4 |
||||
|
a 21, 72 . |
|
|
|
|||||
5 |
|
|
|
|
|||||
|
|
f x, y 2x2 12x 3y3 63y2 297y 385 . |
|
|
|
||||
6 |
|
|
|
|
|||||
|
|
f x, y 4x2 8x y2 6y 2x y 15 0. |
|
||||||
7 |
|
|
|
|
|
|
|
||
|
f x, y x 2 2 y 6 2 16 |
|
ABC |
|
A 0, 0 , |
||||
|
B 6, 0 C 0, 18 . |
|
|
|
|
|
8
2%,
6% 4%.
3 104 ., 9 104
27 1012 .
,
K0 3 104, L0 3 102.
k KL
MRSLK
MRSLK
k KL .
19