7£®ÔÚƽÃæÖ±½Ç×ø±êϵxOyÖУ¬ÒÔ×ø±êÔ­µãOΪ¼«µã£¬xÖáÕý°ëÖáΪ¼«ÖὨÁ¢Ö±½Ç×ø±êϵ£¬½«ÇúÏßC1$\left\{\begin{array}{l}{x=cos¦È}\\{y=sin¦È}\end{array}\right.$£¨¦ÈΪ²ÎÊý£©ÉÏËùÓеãµÄºá×ø±ê¡¢×Ý×ø±ê·Ö±ðÉ쳤ΪԭÀ´µÄ2ºÍ$\frac{1}{2}$ºóµÃµ½ÇúÏßC2£®
£¨1£©ÇóÇúÏßC1µÄ¼«×ø±ê·½³ÌºÍÇúÏßC2µÄÆÕͨ·½³Ì£»
£¨2£©ÒÑÖªÖ±Ïß1£º¦Ñ£¨cos¦È+2sin¦È£©=4£¬µãPÔÚÇúÏßC2ÉÏ£¬ÇóµãPµ½Ö±ÏßlµÄ¾àÀëµÄ×îСֵ£®

·ÖÎö £¨1£©ÏÈÇó³öÇúÏßC1µÄÆÕͨ·½³Ì£¬ÔÙÇóÇúÏßC1µÄ¼«×ø±ê·½³ÌΪ¦Ñ2=1£®ÓÉÉìËõ±ä»»µÃÇúÏßC2$\left\{\begin{array}{l}{\frac{x}{2}=cos¦È}\\{2y=sin¦È}\end{array}\right.$£¬ÓÉ´ËÄÜÇó³öÇúÏßC2µÄÆÕͨ·½³Ì£®
£¨2£©ÏÈÇó³öÖ±ÏßlµÄÖ±½Ç×ø±ê£¬ÉèP£¨2cos¦È£¬$\frac{sin¦È}{2}$£©£¬Çó³öµãPµ½Ö±ÏßlµÄ¾àÀ룬ÀûÓÃÈý½Çº¯ÊýµÄÐÔÖÊÄÜÇó³öµãPµ½Ö±ÏßlµÄ¾àÀëµÄ×îСֵ£®

½â´ð ½â£º£¨1£©¡ß½«ÇúÏßC1$\left\{\begin{array}{l}{x=cos¦È}\\{y=sin¦È}\end{array}\right.$£¨¦ÈΪ²ÎÊý£©£¬
¡àÇúÏßC1µÄÆÕͨ·½³ÌΪx2+y2=1£¬
¡àÇúÏßC1µÄ¼«×ø±ê·½³ÌΪ¦Ñ2=1£®
¡ßÇúÏßC1$\left\{\begin{array}{l}{x=cos¦È}\\{y=sin¦È}\end{array}\right.$£¨¦ÈΪ²ÎÊý£©ÉÏËùÓеãµÄºá×ø±ê¡¢×Ý×ø±ê·Ö±ðÉ쳤ΪԭÀ´µÄ2ºÍ$\frac{1}{2}$ºóµÃµ½ÇúÏßC2£¬
¡àÇúÏßC2$\left\{\begin{array}{l}{\frac{x}{2}=cos¦È}\\{2y=sin¦È}\end{array}\right.$£¬
¡àÇúÏßC2µÄÆÕͨ·½³ÌΪ$\frac{{x}^{2}}{4}+4{y}^{2}$=1£®
£¨2£©¡ßÖ±Ïß1£º¦Ñ£¨cos¦È+2sin¦È£©=4£¬
¡àÖ±ÏßlµÄÖ±½Ç×ø±ê·½³ÌΪx+2y-4=0£¬
¡ßµãPÔÚÇúÏßC2ÉÏ£¬¡àÉèP£¨2cos¦È£¬$\frac{sin¦È}{2}$£©£¬
¡àµãPµ½Ö±ÏßlµÄ¾àÀëd=$\frac{|2cos¦È+sin¦È-4|}{\sqrt{5}}$=$\frac{|\sqrt{5}sin£¨¦È+¦Á£©-4|}{\sqrt{5}}$¡Ý$\frac{4-\sqrt{5}}{\sqrt{5}}$=$\frac{4\sqrt{5}-5}{5}$£®
¡àµãPµ½Ö±ÏßlµÄ¾àÀëµÄ×îСֵΪ$\frac{4\sqrt{5}-5}{5}$£®

µãÆÀ ±¾Ì⿼²éÇúÏߵļ«×ø±ê·½³Ì¡¢ÆÕͨ·½³ÌµÄÇ󷨣¬¿¼²éµãµ½Ö±ÏߵľàÀëµÄ×îСֵµÄÇ󷨣¬ÊÇ»ù´¡Ì⣬½âÌâʱҪÈÏÕæÉóÌ⣬עÒ⼫×ø±ê·½³Ì¡¢²ÎÊý·½³Ì¡¢¼«×ø±ê·½³ÌµÄÏ໥ת»¯¹«Ê½µÄºÏÀíÔËÓã®

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

18£®ÒÑÖªM={x|log${\;}_{\frac{1}{2}}$2x-11log2x+9¡Ü0}£¬Çóx¡ÊMʱ£¬f£¨x£©=£¨log2$\frac{x}{2}$£©•£¨log${\;}_{\frac{1}{2}}$$\frac{8}{x}$£©µÄ×îÖµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

19£®¡÷ABCÖУ¬AB=6£¬AC=8£¬Èô$\overrightarrow{DB}$$+\overrightarrow{DC}$=0£¬Ôò$\overrightarrow{AD}$$•\overrightarrow{BC}$=14£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

16£®Èçͼ£¬ÔÚÕý·½ÌåABCD-A1B1C1D1ÖУ¬Ìå¶Ô½ÇÏßA1CÓëÃæ¶Ô½ÇÏßDBÒìÃæÇÒ´¹Ö±£®
£¨1£©ÇëÔÚ¸ÃÕý·½ÐÎÖУ¬ÁíÕÒÒ»×é¾ßÓÐÕâÑù¹ØϵµÄ¶Ô½ÇÏߣº£¨¿ÉÒÔÊÇͼÐÎÖл¹Î´»­³öÀ´µÄ£¬Ò²¿ÉÒÔÊÇÒѾ­»­³öÀ´µÄ£©£¨2£©ÈôÕý·½ÌåµÄÀⳤΪ2cm£¬ÇóÖ±ÈýÀâÖùABD-A1B1D1µÄÌå»ý£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

2£®ÒÑÖªf£¨x£©=x3+ax2+bx+cÔÚx=1£¬x=-$\frac{2}{3}$ʱȡµÃ¼«Öµ£®
£¨1£©Çóa£¬bµÄÖµ£»
£¨2£©Èôx¡Ê[-1£¬2]£¬f£¨x£©È¡Öµ·¶Î§£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

12£®Èôx£¬yÂú×ãÔ¼ÊøÌõ¼þ$\left\{\begin{array}{l}{x+y¡Ý2}\\{2x-y¡Ü4}\\{x-y¡Ý0}\end{array}\right.$£¬Ôòz=x+2yµÄ×îСֵΪ2£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

19£®¸÷ÏÊÇÕýÊýµÄµÈ±ÈÊýÁÐ{an}£¬Èôa2£¬$\frac{1}{2}$a3£¬2a1³ÉµÈ²îÊýÁУ¬Ôò$\frac{{a}_{3}+{a}_{4}}{{a}_{4}+{a}_{5}}$µÄֵΪ£¨¡¡¡¡£©
A£®2B£®2»ò-1C£®$\frac{1}{2}$D£®$\frac{1}{2}$»ò-1

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

16£®º¯Êýy=2sinx£¨x¡Ê[0£¬¦Ð]£©µÄÖµÓòΪ[1£¬2]£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

17£®ÒÑÖªº¯Êýf£¨x£©=2sinxcosx+2$\sqrt{3}{cos^2}x-\sqrt{3}$µÄ×îСÕýÖÜÆÚÊǦУ¬µ¥µ÷µÝ¼õÇø¼äÊÇ[k¦Ð+$\frac{¦Ð}{12}$£¬k¦Ð+$\frac{7¦Ð}{12}$]£¬k¡ÊZ£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸