µ±Ç°Î»ÖãºÊ×Ò³ > ¸ßµÈÊýѧ×÷Òµ¼°´ð°¸ ¾«Æ·
£¨1£©z?xsinyy£»£¨2£©z?ln(xy)£»£¨3£©z?(1?xy). x2£®ÇóÏÂÁк¯ÊýµÄ¶þ½×Æ«µ¼Êý£º
y22£»£¨2£©z?3x?y. xx23£®Éèf(x,y)?x?(y?1)arcsin£¬Çófx?(x,1).
y£¨1£©z?arctan?2u?2u224£®É躯Êýu?f(r)¶þ½×¿Éµ¼£¬ÇÒÂú×ã·½³Ì2?2?4£¬ÆäÖÐr?x?y£¬Çóf(r).
?x?y2[f(r)?r?C1lnr?C2]
¶àÔªº¯Êý΢·Öѧ×÷Òµ3
1£®ÇóÏÂÁк¯ÊýµÄȫ΢·Ö£º £¨1£©z?xy?2£®Çóº¯Êýz?x£»£¨2£©z?yyx2?y2£»£¨3£©z?x.
yyµ±x?2£¬y?1£¬?x?0.1£¬?y??0.2ʱµÄÈ«ÔöÁ¿ºÍȫ΢·Ö. x[?z??0.119£¬dz??0.125]
333£®¼ÆËã(1.02)?(1.97)µÄ½üËÆÖµ.[2.95]
?z?z?y2?2x£¬?2xy?3£¬ÇÒz(0,0)?0£¬Çóz?f(x,y)µÄ±í´ïʽ.
?y?x22[z?xy?x?3y]
4£®ÒÑÖª
¶àÔªº¯Êý΢·Öѧ×÷Òµ4
1£®Éèz?u£¬u?2x?3y£¬v?xy£¬Çó
2v?z. ?x2£®Çóz?f(xy,2x?3y)µÄÒ»¡¢¶þ½×Æ«µ¼Êý.
22224323£®ÒÑÖªf(x,x)?x?2x?x£¬f1?(x,x)?2x?2x?1£¬Çóf2?(x,x).[2x?2x?1]
?u?x?2y?2z?2z?2z?2z?0¼ò»¯Îª?0£¬Çó³£Êýa.[3] 4£®Éè±ä»»?¿É°Ñ·½³Ì62?2?v?x?ay?x?y?x?y?u?v?uu5£®Éèz?f(x,y)¾ßÓжþ½×Á¬ÐøÆ«µ¼Êý£¬x?ecosv£¬y?esinv£¬ÊÔÖ¤£º
2?2z?2z?2z2u?z?2?e(2?2). 2?u?v?x?y¶àÔªº¯Êý΢·Öѧ×÷Òµ5
1£®Éè
xz?z?z?ln£¬Çó¡¢. zy?x?y2£®Éèx?2y?z?2xyz?0£¬Çódz.
?2z3£®Éèz?3xyz?a£¬Çó.
?x?yf1??yzf2??z4£®Éèz?f(x?y?z,xyz)£¬Çó.[]
?x1?f1??xyf2?zz5£®ÉèF(u,v)¾ßÓÐÁ¬ÐøÆ«µ¼Êý£¬Ö¤Ã÷ÓÉ·½³ÌF(x?,y?)?0ËùÈ·¶¨µÄº¯Êýz?f(x,y)yx33 5
Âú×ãx?z?z?y?z?xy. ?x?y¶àÔªº¯Êý΢·Öѧ×÷Òµ6
231£®ÔÚÇúÏßx?t,y?t,z?tÉÏÇóÒ»µã£¬Ê¹ÇúÏßÔڴ˵ãµÄÇÐÏ߯½ÐÐÓÚÆ½Ãæx?2y?z?1. [(?1,1,?1)»ò(?1/3,1/9,?1/27)]
?x2?y2?z2?62£®ÇóÇúÏß?2ÔÚµã(1,1,2)´¦µÄÇÐÏß¼°·¨Æ½Ãæ·½³Ì.[ÇÐÏòÁ¿Æ½ÐÐÓÚ(0,?2,1)] 22?z?y?x?42223£®ÇóÇúÃæax?by?cz?1ÔÚµã(x0,y0,z0)´¦µÄÇÐÆ½Ãæ·½³Ì.[axx0?byy0?czz0?1]
x24£®ÇóÇúÃæz??y2ƽÐÐÓÚÆ½Ãæ2x?2y?z?0µÄÇÐÆ½Ãæ·½³Ì.[2x?2y?z?3?0]
2xy5£®ÊÔÖ¤ÇúÃæf(x?az,y?bz)?0ÉÏÈÎÒ»µã´¦µÄÇÐÆ½ÃæÓëÖ±ÏßL:??zƽÐУ¬ÆäÖÐf¿É
ab΢£¬a,bΪ³£Êý.
¶àÔªº¯Êý΢·Öѧ×÷Òµ7
1£®Çóº¯Êýf(x,y)?x?3xy?3xy?3xµÄ¼«Öµ.
[¼«Ð¡Öµf(2,1)??4£¬¼«´óÖµf(?2,?1)?4]
2£®Ä³³§¼ÒÉú²úÁ½ÖÖ²úÆ·¢ñºÍ¢ò£¬³öÊÛµ¥¼Û·Ö±ðΪ10ÔªÓë9Ôª£¬Éú²úxµ¥Î»µÄ²úÆ·¢ñÓëÉú²úyµ¥Î»µÄ²úÆ·¢òµÄ×Ü·ÑÓÃÊÇ£º
322400?2x?3y?0.01(3x2?xy?3y2)£¨Ôª£©
¼Ù¶¨ÏúÊÛÁ¿µÈÓÚÉú²úÁ¿.ÇóÈ¡µÃ×î´óÀûÈóʱ£¬Á½ÖÖ²úÆ·µÄ²úÁ¿¸÷¶àÉÙ£¿[x?120£¬y?80] 3£®ÒªÔìÒ»¸öÈÝ»ýµÈÓÚkµÄ³¤·½ÌåÎÞ¸ÇË®³Ø£¬Ó¦ÈçºÎÑ¡ÔñË®³ØµÄ³ß´ç£¬·½¿ÉʹËüµÄ±íÃæ»ý×îС.[µ±³¤¡¢¿í¶¼ÊÇ32k£¬¶ø¸ßΪ32k/2ʱ£¬±íÃæ»ý×îС]
4£®ÔÚµÚÒ»ØÔÏÞÄÚ×÷ÍÖÇòÃæ4x?4y?z?4µÄÇÐÆ½Ã棬ʹËüÔÚÈý¸ö×ø±êÖáÉÏµÄ½Ø¾àÆ½·½ºÍ×îС£¬Çó¸ÃÇÐÆ½ÃæµÄ·½³Ì.[2x?2y?2z?4]
ÖØ»ý·Ö×÷Òµ1
1£®»³ö»ý·ÖÇøÓò£¬²¢¼ÆËãÏÂÁжþÖØ»ý·Ö£º
222sinxd?£¬DÓÉy?x£¬y?2x¼°x?2ËùΧ£»[1?cos2] ??xD1162x4£¨2£©??yed?£¬DÓÉy?x£¬x?2¼°xÖáËùΧ£»[(e?1)]
6D1322£¨3£©??(x?y?x)d?£¬DÓÉy?x£¬y?2x¼°y?2ËùΧ£»[]
6D12£¨4£©??ysinxd?£¬DÓÉx?y£¬y?1¼°yÖáËùΧ£»[(1?sin1)]
2D£¨1£©£¨5£©
143ed?x?y£¬ÓÉ£¬¼°ËùΧ.[y?2(e?4e)] y?xD??2D?xy2£®»³ö»ý·ÖÇøÓò£¬²¢½»»»»ý·Ö´ÎÐò£º £¨1£©£¨3£©
?40dx?tanx0£¨2£©?dx?f(x,y)dy£»
122x?x22?xf(x,y)dy£»
?20dy?2yy2£¨4£©?dy?f(x,y)dx£»
022yyf(x,y)dx.
6
3£®¼ÆËãI?4£®¼ÆËãI??20dx?2xy1?y3yyxdy.[
14] 3yy2?1214dy?12edx??1dy?2231edx.[e?e]
821] 6yx5£®ÇóÓÉÆ½Ãæx?y?1£¬ÇúÃæz?x?y¼°Èý×ø±êÃæËùΧÁ¢ÌåµÄÌå»ý.[ÖØ»ý·Ö×÷Òµ2
1£®»¯ÏÂÁлý·ÖΪ¼«×ø±êÐÎʽµÄ¶þ´Î»ý·Ö£º £¨1£©
?10dx?ex22x?x2x£¨2£©?dy?f(x,y)dy£»
012?yyf(x,y)dx.
2£®ÀûÓü«×ø±ê¼ÆËãÏÂÁжþÖØ»ý·Ö£º £¨1£©£¨2£©
???y2Dd?£¬DÓÉÔ²ÖÜx2?y2?4ËùΧ£»[?(e4?1)]
yd?£¬DÓÉÔ²ÖÜx2?y2?1£¬x2?y2?4¼°Ö±Ïßy?0£¬y?xËùΧ³ÉµÄ??Dx2ÔÚµÚÒ»ÏóÏÞÄڵıÕÇøÓò£»[3?/64]
arctan??£¨4£©??£¨3£©
D(x?y)22?12d?£¬DÓÉy?x2£¬y?xËùΧ£»[2?1]
D(x2?y2)d?£¬DÓÉy?4x?x2£¬y?0ËùΧ.[12?]
223£®ÇóÓÉÇúÃæz?4?x?yÓëz?0ËùΧÁ¢ÌåµÄÌå»ý.[8?]
ÖØ»ý·Ö×÷Òµ3 1£®»¯»ý·ÖI?2???f(x,y,z)dvΪÈý´Î»ý·Ö£¬ÆäÖÐ?·Ö±ðÊÇ£º
?222£¨1£©ÓÉz?x?2y¼°z?3?2x?yËùΧ£» £¨2£©ÓÉy?x£¬z?0¼°z?4?yËùΧ. 2£®¼ÆËãÈýÖØ»ý·Ö[
2dxdydz£¬ÆäÖÐ?ÓÉx?y?z?1¼°Èý×ø±êÃæËùΧ. 3???(1?x?y?z)?15(ln2?)] 282223£®ÇóÓÉÇúÃæz?2?xÓëz?x?2yËùΧÁ¢ÌåµÄÌå»ý.[?] 4£®¼ÆËãÈýÖØ»ý·Ö
32????xysinz4dv£¬ÆäÖÐ?ÓÉy?x£¬y?2x£¬z??2¼°z?xËùΧ.
22?1?4(1?cos)] [
1816ÖØ»ý·Ö×÷Òµ4
1£®¼ÆËãÈýÖØ»ý·Ö2£®¼ÆËãÈýÖØ»ý·Ö
224zx?y?2z?(e?1)] £¬ÆäÖÐÊÇÓÉÓëËùÎ§ÇøÓò.[edv?z?2???2????xz?x2?y2dv£¬ÆäÖÐ?ÊÇÓÉz?x2?y2Óëx2?y2?z2?2ËùΧÁ¢
ÌåÇøÓòÔÚµÚÒ»ØÔÏÞ²¿·Ö.[1/12] 3£®¼ÆËãÈýÖØ»ý·Ö[128?/15]
7
2222z?4?x?y£¬ÆäÖÐÊÇÓÉÓëz?0ËùÎ§ÇøÓò. (x?y)dv?????4£®ÇóÓÉÇúÃæz?6?x?yÓëz?5£®ÇóÓÉÇúÃæz?1£®¼ÆËãÇú̾̾»ý
22x2?y2ËùΧÁ¢ÌåµÄÌå»ý.[32?/3]
ÖØ»ý·Ö×÷Òµ5
2?x2?y2Óëz?x2?y2ËùΧÁ¢ÌåµÄÌå»ý.[4?(2?1)/3]
£¨1£©Ë«ÇúÅ×ÎïÃæz?x?y±»Ô²ÖùÃæx?y?1ºÍx?y?4½Ø³öµÄ²¿·Ö£» [?(1717?55)/6] £¨2£©ÉϰëÇòÃæz?2222224?x2?y2ÔÚÔ²ÖùÃæx2?y2?2xÄÚ²¿µÄ²¿·Ö£»[4(??2)]
2£¨3£©ÇúÃæz?2?3x?2y£¬(x,y)?D£¬ÆäÖÐDÊÇxOyÃæµÄÈý½ÇÐΣ¬Æä¶¥µã·Ö±ðΪ(0,0)£¬
(0,1)ºÍ(2,1).[(1326?510)/12]
x2y24b2£®ÉèÒ»±¡°åËùÕ¼µÄÇøÓòΪD:2?2?1,y?0£¬ÇÒÃܶȾùÔÈ£¬Çó´Ë±¡°åµÄÖÊÐÄ.[(0,)]
ab3?223£®Éè?ÊÇÓÉÇúÃæz?2x?2yºÍÆ½Ãæz?4ËùÎ§ÇøÓò.Ò»ÎïÌåÕ¼ÓÐÇøÓò?£¬ÇÒÃܶȾùÔÈ£¬Çó´ËÎïÌåµÄÖÊÐÄ.[(0,0,8/3)]
ÇúÏß»ý·Ö×÷Òµ1
1£®¼ÆËãÏÂÁжԻ¡³¤µÄÇúÏß»ý·Ö£º
?£¨2£©?£¨3£©?£¨1£©£¨4£©
LLx3y2ds£¬ÆäÖÐLΪ°ëÔ²ÖÜx?4?y2£»[256/15]
y2ds£¬ÆäÖÐLΪ°ÚÏßx?a(t?sint)£¬y?a(1?cost)µÄÒ»¹°£»[256a3/15] yds£¬ÆäÖÐLΪÓÉÖ±Ïßy?x¼°Å×ÎïÏßx?y2ËùΧ³ÉµÄÇøÓòµÄÕû¸ö±ß½ç£»
x2?y2L[(55?62?1)/12]
?3Leds£¬ÆäÖÐLΪԲÖÜx2?y2?a2£¬Ö±Ïßy?x¼°xÖáÔÚµÚÒ»ÏóÏÞÄÚËùΧÉÈÐÎ
aµÄÕû¸ö±ß½ç.[e(2??a/4)?2]
22222£®ÉèLΪÇòÃæx?y?z?a±»Æ½Ãæx?y?z?0Ëù½ØµÃµÄÔ²ÖÜ£¬ÇóI??Ly2ds.
[2?a/3]
ÇúÏß»ý·Ö×÷Òµ2
1£®¼ÆËã
?(x?y)dx?(y?x)dy£¬ÆäÖÐLÊÇ£º
L£¨1£©Å×ÎïÏßy?xÉÏ´Óµã(1,1)µ½µã(4,2)µÄÒ»¶Î»¡£»[34/3] £¨2£©´Óµã(1,1)µ½µã(4,2)µÄÖ±Ï߶Σ»[11]
£¨3£©ÏÈÑØÖ±Ïß´Óµã(1,1)µ½µã(1,2)£¬È»ºóÔÙÑØÖ±Ïßµ½µã(4,2)µÄÕÛÏߣ»[14] £¨4£©ÇúÏßx?2t?t?1£¬y?t?1ÉÏ´Óµã(1,1)µ½µã(4,2)µÄÒ»¶Î»¡.[32/3]
222??2£®ÉèÒ»¸öÖʵãÔÚM(x,y)´¦Êܵ½Á¦FµÄ×÷Óã¬FµÄ´óСÓëMµ½ÔµãOµÄ¾àÀëÆ½·½³É·´±È£¬?x2y2FµÄ·½ÏòºãÖ¸ÏòÔµã.´ËÖʵãÓɵãA(a,0)ÑØÍÖÔ²2?2?1°´ÄæÊ±Õë·½ÏòÒÆ¶¯µ½µã
ab?B(0,b)£¬ÇóÁ¦FËù×÷µÄ¹¦W.[k(b?1?a?1)]
ÇúÏß»ý·Ö×÷Òµ3
1. ¼ÆËãÇúÏß»ý·Ö
??L(2xy?y2)dx?x2dy£¬ÆäÖÐLÊÇÓÉÇúÏßy?1?x2ÓëxÖáËùÎ§ÇøÓò
DµÄÕýÏò±ß½çÇúÏß.[4/3]
8
2£®¼ÆËãÇúÏß»ý·Ö
?L(y?x2y)dx?(x?xy2)dy£¬ÆäÖÐLÊÇÑØÉϰëÔ²ÖÜy?2x?x2´ÓÔ
µãµ½µã(2,0)µÄ»¡¶Î.[?3?/4] 3£®Ö¤Ã÷ÇúÏß»ý·Ö[2?sin2]
4£®Éèdz?(2?y?3x)dx?(2y?ax)dy£¬ÇÒz(0,0)?1£¬Çó³£Êýa¼°z(x,y)µÄ±í´ïʽ. [a??1£¬z?2x?xy?x?y?1]
322?(1,1)(0,0)(3x2?y)dx?(4sin2y?x)dyÓë·¾¶Î޹أ¬²¢¼ÆËã»ý·ÖÖµ.
xdy?ydx??22£¬ÆäÖÐLÊÇÒÔµã(1,0)ΪÖÐÐÄ£¬RΪ°ë¾¶µÄÔ²ÖÜ
5£®¼ÆËãÇúÏß»ý·ÖI?Lx?y£¨R?1£©£¬È¡ÄæÊ±Õë·½Ïò.[2?]
9
¹²·ÖÏí92ƪÏà¹ØÎĵµ