.
a 11 x 2+ a 22 y 2+ a 33 z 2+ 2 a 12 xy + 2 a 13 xz + 2 a 23 yz +
+ 2 a 1 x + 2 a 2 y + 2 a 3 z + = 0. (18)
, , , 2 a 1 x + 2 a 2 y + 2 a 3 z , .
(18) . k (). (x ¢, y ¢, z ¢), k () (13). , , (14¢), x, y, z x ¢, y ¢, z ¢, . , ; (13).
l1 x ¢2 + l2 y ¢2 + l3 z ¢2 + 2 b 1 x ¢ + 2 b 2 y ¢ + 2 b 3 z ¢ + ¢ = 0.
, . , l1, l2, l3, b 1, b 2, b 3 . :
l1 - + l2- +
+ l3 - + ¢ = 0.
,
d = ¢- - -,
l12+ l22+ l32+ d = 0.
x ²= x ¢+ b 1/l1,
y ²= y ¢+ b 2/l2,
z ²= z ¢+ b 3/l3.
( ) O ¢(- b 1/l1,- b 2/l2,- b 3/l3) Ox ¢ y ¢ z ¢. , O ¢ Ox ¢ y ¢ z ¢.
l1(x ²)2 + l2(y ²)2 + l3(z ²)2 + d = 0. (19)
, - b 1, b 2, b 3 ; , b 1= 0 x ²= x ¢. l1= 0, 2 b 1 x ¢ . x ¢ . l2= 0 y ¢, l3= 0 z ¢.
, l1, l2, l3 . , l3 = 0 ( , ).
l1(x ²)2 + l2(y ²)2 + 2 b 3 z ¢ + d = 0. (20)
d = ¢- b 12/l1 - b 22/l2. :
l1(x ²)2 + l2(y ²)2 + 2 b 3(z ¢ + d /2 b 3) = 0
z ²= z ¢ + d /2 b 3. , z ²= 2 b 3 z ¢ + d , .. .
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l1(x ²)2 + l2(y ²)2 = -2 b 3 z ². (21)
:
x ²= x ¢+ b 1/l1,
y ²= y ¢+ b 2/l2,
z ²= z ¢ + d /2 b 3,
O ¢(- b 1/l1,- b 2/l2,- d /2 b 3) Ox ¢ y ¢ z ¢.
, l1, l2, l3 . , l1¹0.
l1(x ²)2 +2 b 2 y ¢ + 2 b 3 z ¢ + d = 0. (22)
. , y ¢ z ¢ y ². , .
y ²= (b 2/ k) y ¢ + (b 3/ k) z ¢,
z ²= - (b 2/ k) y ¢ - (b 3/ k) z ¢,
k =. ,
l1(x ²)2 +2 ky ²+ d = 0. (23)
. 7 , , , (23) (22). , , (20)
l1(x ²)2 = -2 ky ². (24)
, (19), (21) (24). ,
l1(x ²)2 + l2(y ²)2 + l3(z ²)2 + d = 0;
l1(x ²)2 + l2(y ²)2 = -2 b 3 z ²;
l1(x ²)2 = -2 ky ².
, l1, l2, l3, b 3, d, . .
. .
4. Oxy
3 y 2 - 4 xy + 4 x + 2 y 1 = 0. (25)
. Oxy.
.
k () = 3 y 2 - 4 xy
. A k () A - l E:
A = , A - l E =.
, det(A - l E) . :
l2 - (tr A)l + det A = 0.
l2 - 3l - 4 = 0.
l1= 4, l2 = -1. A - l1 E A - l2 E:
A - 4 E =, A + E =.
:
-4 x - 2 y = 0, x - 2 y = 0,
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-2 x - y = 0, -2 x + 4 y = 0,
(1,-2), (2, 1). || = , || = .
,,
{, }
=.
, :
x = x ¢ + y ¢, x ¢ = x - y,
y = x ¢ + y ¢, y ¢ = x + y,
k ()
k () = l1 x ¢2 + l2 y ¢2 = 4 x ¢2 - y ¢2.
, , (25) (26).
4 x ¢2 - y ¢2 + 4 + 2 1 = 0.
, :
4 x ¢2 - y ¢2 + 2 y ¢ 1 = 0.
y ¢ :
4 x ¢2 - (y ¢2 - 2 y ¢ + ()2) + ()2 1 = 0.
4 x ¢2 - (y ¢ - )2 + 5 1 = 0.
:
x ²= x ¢,
y ²= y ¢ - ,
O ¢(0, ) Ox ¢ y ¢.
4(x ²)2 - (y ²)2 = -4.
-(x ²)2 + = 1 (27)
, O ¢ y ², 1 2.
, , . (26) Oxy:
x = 0 + = 2, y = 0 + =1.
O ¢(2, 1) Oxy. O ¢ x ² O ¢ y ² (1,-2) (2, 1). O ¢ .
, ( | x ²| =1, | y ²| = 2) , . , . O ¢ y ², , .
y | |||||||||||||||||||||||
y ² | |||||||||||||||||||||||
O ¢ | |||||||||||||||||||||||
x | |||||||||||||||||||||||
O | |||||||||||||||||||||||
x ² | |||||||||||||||||||||||
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5. Oxyz
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3 y 2 + 4 xy - 2 xz - 4 yz + 2 x +14 y = 0.
.
. 3: k () = 3 y 2 + 4 xy - 2 xy - 4 yz. , ,
k () = - x ¢2 - y ¢2 + 5 z ¢2,
(17). : 2 x +14 y, :
- x ¢2 - y ¢2 + 5 z ¢2 + 2 +14
, :
- x ¢2 - y ¢2 + 5 z ¢2 + x ¢- 4 y ¢+ 5 z ¢ = 0.
:
-(x ¢2 - x ¢ + (/2)2) + - (y ¢2 + 4 y ¢+ (2)2) +12 +
+ 5(z ¢2 + z ¢ + (/2)2) - = 0.
-(x ¢- /2)2 - (y ¢ + 2)2 +5(z ¢ + /2)2 + 5 = 0.
:
x ²= x ¢- /2,
y ²= y ¢ + 2,
z ²= z ¢ + /2.
O ¢(/2, 2,-/2) Ox ¢ y ¢ z ¢.
-(x ²)2 - (y ²)2 +5(z ²)2 = -5.
-5
+ - (z ²)2 = 1.
. O ¢ . (17). O ¢(-2,1,3) Oxyz.
, l1, l2, l3 . .
6. Oxyz
4 x 2 + 2 y 2 + 3 z 2 + 4 xz - 4 yz + 6 x - 6 y = 0.
.
. A A - l E:
A =, A - l E =.
:
tr A = 4 + 2 + 3 = 9,
I2(A) = + + = 8 + 2 + 8 = 18,
det A = = 2 = 20 = 0
( , ). (6):
-l3 + 9l2 - 18l + 0 = 0 Û l(l2 9l +18) = 0.
l1 = 0, l2 = 3, l3 = 6.
A - 0 E =,
: 1 2 x y z, .
x = -0,5 z,
y = z,
- z - 2 z + 3 z = 0.
z , , z = 2 x = -1, y = 2. (1, 2, 2).
A - 3 E =,
A - 6 E =.
( ). (2, 2,-1), (2,-1, 2). , .
l1 = 0, (1, 2, 2),,
l2 = 3, (2, 2,-1),,
l3 = 6, (2,-1, 2),.
. , .
C =.
. : C C=E. :
x ¢= (- x + 2 y + 2 z), x = (- x ¢ + 2 y ¢ + 2 z ¢),
y ¢= (2 x + 2 y - z), y = (2 x ¢ + 2 y ¢ - z ¢),
z ¢= (2 x - y + 2 z), z = (2 x ¢ - y ¢ + 2 z ¢),
, .
0 x ¢2 + 3 y ¢2 + 6 z ¢2 + (- x ¢ + 2 y ¢ + 2 z ¢) - (2 x ¢ + 2 y ¢ - z ¢) = 0,
3 y ¢2 + 6 z ¢2 - 6 x ¢ + 6 z ¢ = 0.
3 z ¢; x ¢ .
y ¢2 + 2(z ¢2 + z ¢ + ) - - 2 x ¢ = 0,
y ¢2 + 22= 2 .
:
x ²= x ¢ + 1/4,
y ²= y ¢,
z ²= z ¢ + 1/2.
O ¢(-1/4, 0,-1/2) Ox ¢ y ¢ z ¢.
(y ²)2 + 2(z ²)2 = 2 x ² Û + (z ²)2 = x ².
, O ¢ x ².
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, 2.
7. Oxyz
x 2 + y 2 + z 2 + 2 xy + 4 xz + 4 yz + 8 x + 4 y - 5 = 0.
.
. k () = x 2 + y 2 + z 2 + 2 xy + 4 xz + 4 yz . k () A - l E:
A =, A - l E =.
:
tr A = 1 + 1 + 4 = 6,
, , rank A =1 (.. A ), I2(A) = 0 det A = 0. (6):
-l3 + 6l2 = 0 Û l2(l - 6) = 0.
, l1 = 0, l2 = 0, l3 = 6. l3 = 6 (1, 1, 2).
l1 = l2 = 0 1:
, , 2,
x + y + 2 z = 0, (28)
. , , (1,-1, 0). , (22). . : , x ¢ y ¢ ( z ¢). (x, y, z) a 1 x + a 2 y + a 3 z = 0, x ¢, , y ¢. : 4 x + 2 y = 0.
Û
(2,- 4, 1). (x, y, z) (28), , .. (x, y, z) (2,- 4, 1) = 0. , (x, y, z)
Û Û
(3, 1,-2). , .
l1 = 0, (2,- 4, 1),,
l2 = 0, (3, 1,-2),,
l3 = 6, (1, 1, 2),.
, .
x = x ¢ + y ¢ + z ¢,
y = - x ¢ + y ¢ + z ¢,
z = x ¢ - y ¢ + z ¢.
, .
6 z ¢2 + 8 + 4 - 5 = 0,
6 z ¢2 + y ¢ + z ¢ - 5 = 0 Û 3 z ¢2 + y ¢ + z ¢ - 2,5 = 0,
z ¢ :
3 - + y ¢ - 2,5 = 0,
32- + y ¢ - 2,5 = 0,
32+ = 0,
:
x ²= x ¢,
y ²= y ¢ -,
z ²= z ¢ +,
O ¢(0, ,-) Ox ¢ y ¢ z ¢.
3(z ²)2 = - y ².
(z ²)2 = -2 py ², p =. , O ¢ y ², O ¢ x ².
1
1. | + = 1 |
2. (Æ) | + = 1 |
3. | = 1 |
4. | a 2 x 2 b 2 y 2 = 0 |
5. | a 2 x 2 + b 2 y 2 = 0 |
6. | y 2 = 2 p, |
7. | x 2 = a 2 |
8. | x 2 = a 2 |
9. | x 2 = 0 |
2
E | |
1. | + + =1, |
2. (Ø) | + + = 1, |
3. () | + + = 0, |
4. | + = 1, |
5. | + = 1, |
6. | + = 0, |
7. | + = 2 z, |
8. | = 2 z, |
9. | + =1, |
10. | + = 1, |
11. , | + = 0, |
12. | = 1, |
13. | = 0, |
14. | x 2 = 2 py |
15. | x 2 = a 2 |
16. | x 2 = 0 |
17. | x 2 = a 2 |