D , (1.5) (1.6).:
.
, .
, , .
1.4.4
:
.
. ., D .
, , D .
: Û ( 1)2 + 2 = 1; =2; =
:
, , .. , . .
1.4.5
y =ex,
y = 2, Û ex = 2 Þ x = ln 2.
1.4.6 - D, :
. D 3 3- .
1.5.
D .
U V
(1.11)
G .
(1.11) .
(u,v (1.11) )
G.
:
dxdx
du dv
J = = D(x,y)
dy dy D(u,v)
du dv
J ¹ 0, :
(1.12)
1.5.1. ,
D , + = 1, + =2, 2 = 1, 2 = 3.
, .. D 3 .
:
x + y = u, 2x y = v.
uov:
-
,
.
1.6.
, , .
, , , .
1) 2) , , .. .
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.
, .
,
f(x,y) D.
, D , , , , 2- .
r q.
, , .
D , , .
, , :
. (1.13)
, , , , r ³ 0 0 £ q £ 2p.
. (1.14)
D , D .
D, .
D 1) 2) , .
D (1.14).
( Di (i =1,2,..., n) DSi).
Di , ri ri+1 .
. , , D, , .
Di, :
( ri ri + Dri).
.
f(x,y) (xi,hi) Di , ri.
(1.2) . (xi,hi)
( , .. ).
qi , . (xi,hi)
(1.15)
: (1.16)
.. (1.15) f (x,y), f (r cosq, r sinq)r, .
: , , , .. . (xi,hi) Di ( , (xi,hi) Di ).
(1.16) .
(1.16) , :
(1.12),
.
:
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.
, :
1) f(x,y) r cosq r sinq;
2) dxdy r dr dq ( ).
. D .
, , , r q.
a b q.
a , b . ( D) 2 : , r1 = r1(q) r2 = r2(q), r1(q) r2(q) , [a,b]. , D 1)
r1 = r1 (q) ,
r2 = r2 (q)
2) , a b; a < b; r1(q) r2(q) .
, a b. . q a b, q .
D r1 = r1(q), D r2 = r2(q).
:
. (1.17)
1. (.. q, r) , .
2. , .
D , , D , :
.
.1.19
3. , D 1) 2) , 3) 2 + 2.
, .. r2.
1.6.1
:
. (1.18)
. (1.19)
1.6.2 ,
D , 2 + 2 = 2 2 + 2 = 1.
(1.20)
1.6.3 , (D) , : .
.
- . , j D. j ( j< p/2) r . j . j. (. 1.20)
r = 0 j:
( , j < p/2).
, D 0 p/4.
r D r = 0 ,
.
.
1. .
:
1.1 1.2
1.3 1.4
1.5 1.6
2. z = f(x,y) :
2.1 ;
2.2 ;
2.3 ;
2.4 ; -
2.5 ;
2.6 ;
3. z = f (x;y) , :
3.1
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3.2
3.3
3.4
3.5
1.7
, , z = f(x,y), f(x,y) , , - D , , z,
. (1.21)
. , (1.1) D z = f(x,y) . , , = j (x,z) = y (y,z), ( D) z, z, (1.1) .
1. , .
2. f(x,y) £ 0, .
3. z = f2(x,y) ³ 0, z = f1(x,y) ³ 0 ( D),
.
. , f2(x,y) f1(x,y) , f2(x,y) ³ f1(x,y).
, .
, , ( ).
, , , .
1.7.1 , :
.
(.)
1.7.2 , z = 0, x2 + y2 = 2y, z = 4 x2 y2.
.
, z = 4 x 2 y2, D, x2 + y2 = 2y. (. 1.22)
, .
, 2 + 2, . 2 + 2 = 2 , , q D 0 p.
(.).
.
1. , :
1.1 1.4
1.2 1.5
1.3
2. , :
2.1
2.2
2.3
2.4
2.5
3. ,m- . :
3.1
3.2
3.3
3.4
3.5
4. :
4.1
4.2
4.3
4.4
4.5
1.8
f(x,y) º 1 D.
D :
( S- D), ,
.
(r,q)
. (1.22)
1.8.1 D, + 2 = 2 = 2/4 1.
. , : (2;0) (-4;3). (.1.23)
(.).
1.8.2 , = 0, = , 2 + 2 = 2. Þ r2 = 2r os q.
(..).
1.8.3 , 3 + 3= ( ) (. 1.25).
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