8£®ÒÑÖªÍÖÔ²C£º$\frac{{x}^{2}}{{a}^{2}}$+$\frac{{y}^{2}}{{b}^{2}}$=1£¨a£¾b£¾0£©µÄ×ó¡¢ÓÒ½¹µã·Ö±ðΪF1¡¢F2£¬ÓÉÍÖÔ²¶ÌÖáµÄÒ»¸ö¶ËµãÓëÁ½¸ö½¹µã¹¹³ÉÒ»¸öµÈ±ßÈý½ÇÐΣ®ËüµÄÃæ»ýΪ4$\sqrt{3}$£®
£¨1£©ÇóÍÖÔ²CµÄ·½³Ì£»
£¨2£©ÒÑÖª¶¯µãB£¨m£¬n£©£¨mn¡Ù0£©ÔÚÍÖÔ²ÉÏ£¬µãA£¨0£¬2$\sqrt{3}$£©£¬Ö±ÏßAB½»xÖáÓÚµãD£¬µãB¡äΪµãB¹ØÓÚxÖáµÄ¶Ô³Æµã£¬Ö±ÏßAB¡ä½»xÖáÓÚµãE£¬ÈôÔÚyÖáÉÏ´æÔÚµãG£¨0£¬t£©£¬Ê¹µÃ¡ÏOGD=¡ÏOEG£¬ÇóµãGµÄ×ø±ê£®

·ÖÎö £¨1£©ÀûÓÃÍÖÔ²µÄ¶ÌÖáµÄÒ»¸ö¶ËµãºÍÁ½¸ö½¹µã¹¹³ÉµÈ±ßÈý½ÇÐεÄÈý¸ö¶¥µã£¬ËüµÄÃæ»ýΪ4$\sqrt{3}$£®½¨Á¢·½³Ì¹ØÏµ£¬Çó³öa£¬b£¬¼´¿ÉµÃÍÖÔ²·½³Ì£®
£¨2£©ÉèD£¨x1£¬0£©£¬E£¨x2£¬0£©£®ÓÉA£¬D£¬B£¬Èýµã¹²Ïߣ®µÃx1=$\frac{-2\sqrt{3}m}{n-2\sqrt{3}}$£®Í¬Àí¿ÉµÃx2=$\frac{2\sqrt{3}m}{n-2\sqrt{3}}$£®ÓÖ¡ÏOGD=¡ÏOEG£¬µÃ$\frac{OD}{OG}=\frac{OG}{OE}£¬¼´O{G}^{2}=OD•OE$£®ÓÉÓÚ$\frac{{m}^{2}}{16}-\frac{{n}^{2}}{12}=1$£¬¹Ê${t}^{2}=\frac{12}{12-{n}^{2}}¡Á16£¨1-\frac{{n}^{2}}{12}£©=16$£®

½â´ð ½â£º£¨1£©ÓÉÒÑÖªµÃ$\left\{\begin{array}{l}{a=2c}\\{\frac{1}{2}•2c•\sqrt{3}c=4\sqrt{3}}\end{array}\right.$£¬
¡à$a=4£¬b=2\sqrt{3}$£¬¡àÍÖÔ²CµÄ·½³Ì£º$\frac{{x}^{2}}{16}+\frac{{y}^{2}}{12}=1$£®
£¨2£©ÉèD£¨x1£¬0£©£¬E£¨x2£¬0£©£®
ÓÉA£¬D£¬B£¬Èýµã¹²Ïߣ®µÃ$\frac{0-2\sqrt{3}}{{x}_{1}}=\frac{n-2\sqrt{3}}{m}$£¬¼´x1=$\frac{-2\sqrt{3}m}{n-2\sqrt{3}}$£®
ͬÀí¿ÉµÃx2=$\frac{2\sqrt{3}m}{n-2\sqrt{3}}$£®
ÓÖ¡ß¡ÏOGD=¡ÏOEG£¬¡à$\frac{OD}{OG}=\frac{OG}{OE}£¬¼´O{G}^{2}=OD•OE$£®
¡ß-2$\sqrt{3}$$£¼n£¼2\sqrt{3}$£¬ÇÒn¡Ù0£¬¡à${t}^{2}=\frac{-12{m}^{2}}{{n}^{2}-12}=\frac{12{m}^{2}}{12-{n}^{2}}$£¬
ÓÉÓÚ$\frac{{m}^{2}}{16}-\frac{{n}^{2}}{12}=1$£¬¡à${t}^{2}=\frac{12}{12-{n}^{2}}¡Á16£¨1-\frac{{n}^{2}}{12}£©=16$£¬
¡àt=¡À4£¬µãGµÄ×ø±êΪ£¨0£¬¡À4£©£®

µãÆÀ ±¾Ì⿼²éÁËÍÖÔ²µÄ·½³Ì£¬Ö±ÏßÓëÍÖÔ²µÄλÖùØÏµ£¬·½³Ì˼ÏëÊǽâÌâµÄ¹Ø¼ü£¬ÊôÓÚÖеµÌ⣮

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

18£®ÎªÁ˵õ½º¯Êýy=2sin£¨3x+$\frac{¦Ð}{6}$£©µÄͼÏó£¬Ö»Ðè°Ñy=2sinxµÄͼÏóÉÏËùÓеĵ㣨¡¡¡¡£©
A£®ÏòÓÒÆ½ÒÆ$\frac{¦Ð}{6}$¸ö³¤¶Èµ¥Î»£¬ÔÙ°ÑËùµÃ¸÷µãµÄºá×ø±êÉ쳤µ½Ô­À´µÄ3±¶£¨×Ý×ø±ê²»±ä£©
B£®Ïò×óÆ½ÒÆ$\frac{¦Ð}{18}$¸ö³¤¶Èµ¥Î»£¬ÔÙ°ÑËùµÃ¸÷µãµÄºá×ø±êËõ¶Ìµ½Ô­À´µÄ$\frac{1}{3}$±¶£¨×Ý×ø±ê²»±ä£©
C£®ÏòÓÒÆ½ÒÆ$\frac{¦Ð}{18}$¸ö³¤¶Èµ¥Î»£¬ÔÙ°ÑËùµÃ¸÷µãµÄºá×ø±êÉ쳤µ½Ô­À´µÄ3±¶£¨×Ý×ø±ê²»±ä£©
D£®Ïò×óÆ½ÒÆ$\frac{¦Ð}{6}$¸ö³¤¶Èµ¥Î»£¬ÔÙ°ÑËùµÃ¸÷µãµÄºá×ø±êËõ¶Ìµ½Ô­À´µÄ$\frac{1}{3}$±¶£¨×Ý×ø±ê²»±ä£©

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

19£®Ä³²úÆ·µÄ¹ã¸æ·ÑÓÃx£¨°ÙÍòÔª£©ÓëÏúÊÛ¶îy£¨°ÙÍòÔª£©µÄͳ¼ÆÊý¾ÝÈç±í£º
x24568
y2533m5575
¸ù¾Ý±íÖÐÊý¾Ý£¬ÓÃ×îС¶þ³Ë·¨µÃ³öyÓëxµÄÏßÐԻع鷽³ÌΪ$\stackrel{¡Ä}{y}$=8.6x+5£¬Ôò±íÖеÄmµÄֵΪ£¨¡¡¡¡£©
A£®46B£®48C£®50D£®52

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

16£®ÒÑÖª¶¯Ô²MÔÚÔ²F1£º£¨x+1£©2+y2=$\frac{1}{4}$ÍⲿÇÒÓëÔ²F1ÏàÇУ¬Í¬Ê±»¹ÔÚÔ²F2£º£¨x-1£©2+y2=$\frac{49}{4}$ÄÚ²¿ÓëÔ²F2ÏàÇУ®
£¨1£©Çó¶¯Ô²Ô²ÐÄMµÄ¹ì¼£·½³Ì£»
£¨2£©¼Ç£¨1£©ÖÐÇó³öµÄ¹ì¼£ÎªC£¬CÓëxÖáµÄÁ½¸ö½»µã·Ö±ðΪA1¡¢A2£¬PÊÇCÉÏÒìÓÚA1¡¢A2µÄ¶¯µã£¬ÓÖÖ±Ïßl£ºx=$\sqrt{6}$ÓëxÖá½»ÓÚµãD£¬Ö±ÏßA1P¡¢A2P·Ö±ð½»Ö±ÏßlÓÚE¡¢FÁ½µã£¬ÇóÖ¤£ºDE•DFΪ¶¨Öµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

3£®ÒÑÖªa=2-1.2£¬b=log36£¬c=log510£¬Ôòa£¬b£¬cµÄ´óС¹ØÏµÊÇ£¨¡¡¡¡£©
A£®c£¼b£¼aB£®c£¼a£¼bC£®a£¼b£¼cD£®a£¼c£¼b

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

13£®µÈ²îÊýÁÐ{an}µÄǰnÏîºÍΪSn£¬ÇÒS5=-15£¬a2+a5=-2£¬Ôò¹«²îdµÈÓÚ£¨¡¡¡¡£©
A£®5B£®4C£®3D£®2

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

20£®ÖÐÐÂÍø2016Äê12ÔÂ19ÈÕµç  ¸ù¾ÝÔ¤±¨£¬½ñÌ쿪ʼÎíö²·¶Î§½«½øÒ»²½À©´ó£¬19ÈÕÒ¹¼äÖÁ20ÈÕ£¬Îíö²×îÑÏÖØµÄʱ¶Î²¿·ÖµØÇøPM2.5Ũ¶È·åÖµ»á³¬¹ý500΢¿Ë/Á¢·½Ã×£¬¶ø´ËÂÖÎíö²×îÑÏÖØµÄʱºò£¬½«ÓаüÀ¨¾©½òÒí¡¢É½Î÷¡¢ÉÂÎ÷¡¢ºÓÄϵÈ11¸öÊ¡ÊÐÔÚÄڵĵØÇø±»Îíö²ÁýÕÖ£¬PM2.5ÊÇÖ¸´óÆøÖÐÖ±¾¶Ð¡ÓÚ»òµÈÓÚ2.5΢Ã׵ĿÅÁ£ÎҲ³ÆÎª¿ÉÈë·Î¿ÅÁ£ÎPM2.5ÈÕ¾ùÖµÔÚ35΢¿Ë/Á¢·½Ã×ÒÔÏÂ¿ÕÆøÖÊÁ¿ÎªÒ»¼¶£»ÔÚ35΢¿Ë/Á¢·½Ãס«75΢¿Ë/Á¢·½Ã×Ö®¼ä¿ÕÆøÖÊÁ¿Îª¶þ¼¶£»ÔÚ75΢¿Ë/Á¢·½Ã×ÒÔÉÏ¿ÕÆøÖÊÁ¿Îª³¬±ê£¬Ä³µØÇøÔÚ2016Äê12ÔÂ19ÈÕÖÁ28ÈÕÿÌìµÄPM2.5¼à²âÊý¾ÝµÄ¾¥Ò¶Í¼ÈçͼËùʾ£º
£¨1£©Çó³öÕâЩÊý¾ÝµÄÖÐλÊýÓ뼫²î£»
£¨2£©´ÓËù¸øµÄ¿ÕÆøÖÊÁ¿²»³¬±êµÄ7ÌìµÄÊý¾ÝÖÐÈÎÒâ³éÈ¡2ÌìµÄÊý¾Ý£¬ÇóÕâ2ÌìÖÐÇ¡ºÃÓÐ1Ìì¿ÕÆøÖÊÁ¿ÎªÒ»¼¶£¬ÁíÒ»Ìì¿ÕÆøÖÊÁ¿Îª¶þ¼¶µÄ¸ÅÂÊ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

17£®ÒÑÖªº¯Êýf£¨x£©=alnx+$\frac{1-{x}^{2}}{{x}^{2}}$£¬a¡ÊR£®
£¨1£©Èôf£¨x£©µÄ×îСֵΪ0£¬ÇóʵÊýaµÄÖµ£»
£¨2£©Ö¤Ã÷£ºµ±a=2ʱ£¬f£¨x£©¡Üf¡ä£¨x£©ÔÚx¡Ê[1£¬2]ÉϺã³ÉÁ¢£¬ÆäÖÐf¡ä£¨x£©±íʾf£¨x£©µÄµ¼º¯Êý£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

18£®ÒÑÖªº¯Êý$f£¨x£©=\frac{x+1}{e^x}$£¬A£¨x1£¬m£©£¬B£¨x2£¬m£©ÊÇÇúÏßy=f£¨x£©ÉÏÁ½¸ö²»Í¬µÄµã£®
£¨¢ñ£©Çóf£¨x£©µÄµ¥µ÷Çø¼ä£¬²¢Ð´³öʵÊýmµÄȡֵ·¶Î§£»
£¨¢ò£©Ö¤Ã÷£ºx1+x2£¾0£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸