8£®½¹µãΪ£¨0£¬6£©£¬ÇÒÓëË«ÇúÏß$\frac{{x}^{2}}{2}$-y2=1ÓÐÏàͬµÄ½¥½üÏßµÄË«ÇúÏß·½³ÌÊÇ£¨¡¡¡¡£©
A£®$\frac{{x}^{2}}{12}$-$\frac{{y}^{2}}{24}$=1B£®$\frac{{y}^{2}}{12}$-$\frac{{x}^{2}}{24}$=1C£®$\frac{{y}^{2}}{24}$-$\frac{{x}^{2}}{12}$=1D£®$\frac{{x}^{2}}{24}$-$\frac{{y}^{2}}{12}$=1

·ÖÎö ¸ù¾ÝÌâÒ⣬ÉèÒªÇóË«ÇúÏߵķ½³ÌΪ$\frac{{x}^{2}}{2}$-y2=k£¬½áºÏ½¹µãµÄλÖÿɵÃk£¼0£¬¿ÉµÃÆä±ê×¼·½³ÌΪ£º$\frac{{y}^{2}}{-k}$-$\frac{{x}^{2}}{-2k}$=1£¬ÓÉË«ÇúÏߵļ¸ºÎÐÔÖʿɵÃc2=£¨-k£©+£¨-2k£©=36£¬½â¿ÉµÃkµÄÖµ£¬´úÈëË«ÇúÏߵıê×¼·½³Ì¼´¿ÉµÃ´ð°¸£®

½â´ð ½â£º¸ù¾ÝÌâÒ⣬ҪÇóË«ÇúÏßÓë$\frac{{x}^{2}}{2}$-y2=1ÓÐÏàͬµÄ½¥½üÏߣ¬¿ÉÒÔÉèÆä·½³ÌΪ£º$\frac{{x}^{2}}{2}$-y2=k£¬
ÓÖÓÉÆä½¹µãΪ£¨0£¬6£©£¬ÔòÆä½¹µãÔÚyÖáÉÏÇÒc=6£¬±ØÓÐk£¼0£¬
¹ÊÆä±ê×¼·½³ÌΪ£º$\frac{{y}^{2}}{-k}$-$\frac{{x}^{2}}{-2k}$=1£¬
ÔòÓÐc2=£¨-k£©+£¨-2k£©=36£¬
½â¿ÉµÃk=-12£»
¹ÊÒªÇóË«ÇúÏߵıê×¼·½³ÌΪ£º$\frac{{y}^{2}}{12}$-$\frac{{x}^{2}}{24}$=1£»
¹ÊÑ¡£ºB£®

µãÆÀ ±¾Ì⿼²éË«ÇúÏߵļ¸ºÎÐÔÖÊ£¬Éæ¼°Ë«ÇúÏߵıê×¼·½³Ì£¬¹Ø¼üÊÇÕÆÎÕ½¥½üÏßÏàͬµÄË«ÇúÏß·½³ÌµÄÉè·¨£®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

18£®Éè{an}ÊÇÊ×Ïî´óÓÚÁãµÄµÈ±ÈÊýÁУ¬Ôò¡°a1£¼a2¡±ÊÇ¡°ÊýÁÐ{an}ÊǵÝÔöÊýÁС±µÄ£¨¡¡¡¡£©
A£®³äÒªÌõ¼þB£®³ä·Ö¶ø²»±ØÒªÌõ¼þ
C£®±ØÒª¶ø²»³ä·ÖÌõ¼þD£®¼È²»³ä·ÖÒ²²»±ØÒªÌõ¼þ

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

19£®¶þÏîʽ£¨x3-$\frac{2}{x}$£©6µÄÕ¹¿ªÊ½Öк¬x-2ÏîµÄϵÊýÊÇ-192£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

16£®ÈçͼËùʾ£¬ÔÚÕý·½ÌåABCD-A1B1C1D1ÖУ¬AB=4£¬M£¬N·Ö±ðΪÀâA1D1£¬A1B1µÄÖе㣬¹ýµãBµÄÆ½Ãæ¦Á¡ÎÆ½ÃæAMN£¬ÔòÆ½Ãæ¦Á½Ø¸ÃÕý·½ÌåËùµÃ½ØÃæµÄÃæ»ýΪ18£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

3£®ÎªÁ˸üºÃµØÈÃѧÉúÊÊÓ¦¸ß¿¼ÍøÉÏÔÄ¾í£¬Ä³Ñ§Ð£Õë¶Ô¸ÃУ20¸ö°à¼¶½øÐÐÁË¡°ºº×ÖÓëÓ¢ÓïÊé·¨´óÈü¡±£¨Ã¿¸ö°à¼¶Ö»ÓÐÒ»¸öÖ¸µ¼ÀÏʦ£©£¬²¢µ÷²éÁ˸÷°à²Î¼Ó¸Ã±ÈÈüµÄѧÉúÈËÊý£¬¸ù¾ÝËùµÃÊý¾Ý£¬·Ö×é³É[0£¬5£©£¬[5£¬10£©£¬[10£¬15£©£¬[15£¬20£©£¬[20£¬25£©£¬[25£¬30£©£¬[30£¬35£©£¬[35£¬40]ʱ£¬Ëù×÷µÄƵÂÊ·Ö²¼Ö±·½Í¼Èçͼ£º
£¨1£©Èç¹û´Ó²Î¼Ó±ÈÈüµÄѧÉúÈËÊýÔÚ25ÈËÒÔÉÏ£¨º¬25ÈË£©µÄ°à¼¶ÖÐËæ»úѡȡ2¸öÖ¸µ¼ÀÏʦ°ä·¢¡°²ÎÓë×éÖ¯½±¡±£¬ÄÇôÖÁÉÙÓÐһλÀ´×Ô¡°²ÎÓëѧÉúÈËÊýÔÚ[25£¬30£©Äڵİ༶¡±µÄÖ¸µ¼ÀÏʦ»ñ½±µÄ¸ÅÂÊÊǶàÉÙ£¿
£¨2£©Èç¹û´Ó²Î¼Ó±ÈÈüµÄѧÉúÈËÊýÔÚ25ÈËÒÔÉÏ£¨º¬25ÈË£©µÄ°à¼¶ÖÐËæ»úѡȡ3¸öÖ¸µ¼ÀÏʦ°ä·¢¡°²ÎÓë×éÖ¯½±¡±£¬Éè¡°²ÎÓëѧÉúÈËÊýÔÚ[25£¬30£©Äڵİ༶¡±µÄÖ¸µ¼ÀÏʦ»ñ½±ÈËÊýΪX£¬ÇóËæ»ú±äÁ¿XµÄ·Ö²¼ÁкÍÊýѧÆÚÍûE£¨X£©£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

13£®É躯Êýf£¨x£©=alnx-bx2£¨x£¾0£©
£¨1£©Èôº¯Êýf£¨x£©µÄͼÏóÔڵ㣨1£¬-$\frac{1}{2}$£©´¦µÄÇÐÏßÓëxÖáÆ½ÐУ¬Ì½¾¿º¯Êýf£¨x£©ÔÚ[$\frac{1}{e}$£¬e]ÉÏÊÇ·ñ´æÔÚ¼«Ð¡Öµ£»
£¨2£©µ±a=1£¬b=0ʱ£¬º¯Êýg£¨x£©=f£¨x£©-kx£¬kΪ³£Êý£¬Èôº¯Êýg£¨x£©ÓÐÁ½¸öÏàÒìÁãµãx1£¬x2£¬Ö¤Ã÷£ºx1£¬x2£¾e2£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

20£®ÒÑÖªx£¬yÂú×ãÔ¼ÊøÌõ¼þ$\left\{\begin{array}{l}{x-y+1¡Ü0}\\{2x+y-a¡Ý0}\\{y-2¡Ü0}\end{array}\right.$£¬ÈôÄ¿±êº¯Êýz=x-2yµÄ×î´óÖµÊÇ-2£¬ÔòʵÊýa=£¨¡¡¡¡£©
A£®-6B£®-1C£®1D£®6

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

17£®ÒÑÖªÇúÏßC1µÄ²ÎÊý·½³ÌÊÇ$\left\{\begin{array}{l}{x=-2+2cos¦È}\\{y=2sin¦È}\end{array}\right.$£¨¦ÈΪ²ÎÊý£©£¬ÒÔ×ø±êÔ­µãΪ¼«µã£¬xÖáµÄÕý°ëÖáΪ¼«Öᣬ½¨Á¢¼«×ø±êϵ£¬ÇúÏßC2µÄ¼«×ø±ê·½³ÌÊǦÑ=4sin¦È£®
£¨¢ñ£©ÇóÇúÏßC1ÓëC2½»µãµÄÆ½ÃæÖ±½Ç×ø±ê£»
£¨¢ò£©A£¬BÁ½µã·Ö±ðÔÚÇúÏßC1ÓëC2ÉÏ£¬µ±|AB|×î´óʱ£¬Çó¡÷OABµÄÃæ»ý£¨OÎª×ø±êÔ­µã£©£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

17£®Ëæ×ÅÎÒ¹ú¾­¼ÃµÄ·¢Õ¹£¬¾ÓÃñµÄ´¢Ðî´æ¿îÖðÄêÔö³¤£®ÉèijµØÇø³ÇÏç¾ÓÃñÈËÃñ±Ò´¢Ðî´æ¿î£¨Äêµ×Óà¶î£©ÈçÏÂ±í£º
Äê·Ý20112012201320142015
ʱ¼ä´úºÅt12345
´¢Ðî´æ¿îy£¨Ç§ÒÚÔª£©567810
£¨1£©Çóy¹ØÓÚtµÄ»Ø¹é·½³Ì$\widehat{y}$=$\widehat{b}$t+$\widehat{a}$
£¨2£©ÓÃËùÇ󻨹鷽³ÌÔ¤²â¸ÃµØÇø2016Ä꣨t=6£©µÄÈËÃñ±Ò´¢Ðî´æ¿î£®
¸½£º»Ø¹é·½³Ì$\widehat{y}$=$\widehat{b}$t+$\widehat{a}$ÖУ¬
$\left\{\begin{array}{l}{b=\frac{\sum_{i=1}^{n}£¨{t}_{i}-\overline{t}£©£¨{y}_{i}-\overline{y}£©}{\sum_{i=1}^{n}£¨{t}_{i}-\overline{t}£©^{2}}=\frac{\sum_{i=1}^{n}{t}_{i}{y}_{i}-n\overline{t}\overline{y}}{\sum_{i=1}^{n}{{t}_{i}}^{2}-n{\overline{t}}^{2}}}\\{a=\overline{y}-b\overline{t}}\end{array}\right.$£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸