8£®ÒÑÖªÇúÏßC1µÄ²ÎÊý·½³ÌΪ$\left\{\begin{array}{l}x=acos¦È\\ y=bsin¦È\end{array}$£¨a£¾b£¾0£¬¦ÈΪ²ÎÊý£©£¬ÇÒÇúÏßC1Éϵĵã$M£¨1£¬\frac{{\sqrt{3}}}{2}£©$¶ÔÓ¦µÄ²ÎÊý¦È=$\frac{¦Ð}{3}$£¬ÒÔÔ­µãOΪ¼«µã£¬xÖáÕý°ëÖáΪ¼«Öᣬ½¨Á¢¼«×ø±êϵ£¬ÇúÏßC2µÄ¼«×ø±ê·½³ÌΪ¦Ñ=2sin¦È£®
£¨1£©Ð´³öÇúÏßC1µÄ¼«×ø±ê·½³ÌÓëÇúÏßC2µÄÖ±½Ç×ø±ê·½³Ì£»
£¨¢ò£©ÒÑÖªµãM1¡¢M2µÄ¼«×ø±ê·Ö±ðΪ$£¨1£¬\frac{¦Ð}{2}£©$ºÍ£¨2£¬0£©£¬Ö±ÏßM1M2ÓëÇúÏßC2½»ÓÚP¡¢QÁ½µã£¬ÉäÏßOPÓëÇúÏßC1½»ÓÚµãA£¬ÉäÏßOQÓëÇúÏßC1½»ÓÚµãB£¬Çó$\frac{1}{{{{|{OA}|}^2}}}+\frac{1}{{{{|{OB}|}^2}}}$µÄÖµ£®

·ÖÎö £¨1£©ÀûÓÃÈýÖÖ·½³ÌµÄ»¥»¯·½·¨£¬¼´¿Éд³öÇúÏßC1µÄ¼«×ø±ê·½³ÌÓëÇúÏßC2µÄÖ±½Ç×ø±ê·½³Ì£»
£¨2£©$A£¨{¦Ñ_1}£¬¦È£©£¬B£¨{¦Ñ_2}£¬¦È+\frac{¦Ð}{2}£©$·Ö±ð´úÈë$\frac{{{¦Ñ^2}{{cos}^2}¦È}}{4}+{¦Ñ^2}{sin^2}¦È=1$ÖУ¬¼´¿ÉÇó$\frac{1}{{{{|{OA}|}^2}}}+\frac{1}{{{{|{OB}|}^2}}}$µÄÖµ£®

½â´ð ½â£º£¨1£©$\left\{\begin{array}{l}1=acos\frac{¦Ð}{3}\\ y=bsin\frac{¦Ð}{3}\end{array}\right.⇒\left\{\begin{array}{l}a=2\\ b=1\end{array}\right.⇒{C_1}£º\frac{x^2}{4}+{y^2}=1$
Òò´ËC1µÄ¼«×ø±ê·½³ÌΪ$\frac{{{¦Ñ^2}{{cos}^2}¦È}}{4}+{¦Ñ^2}{sin^2}¦È=1$${C_2}£º{x^2}+{y^2}=2y$
£¨2£©M1£¨0£¬1£©£¬M2£¨2£¬0£©⇒M1M2£ºx+2y-2=0
Ç¡ºÃ¹ý${C_2}£º{x^2}+{y^2}=2y$µÄÔ²ÐÄ£¬¡àOP¡ÍOQ⇒OA¡ÍOB£¬
¡à$A£¨{¦Ñ_1}£¬¦È£©£¬B£¨{¦Ñ_2}£¬¦È+\frac{¦Ð}{2}£©$
·Ö±ð´úÈë$\frac{{{¦Ñ^2}{{cos}^2}¦È}}{4}+{¦Ñ^2}{sin^2}¦È=1$ÖУ¬
¡à$\frac{1}{{{{|{OA}|}^2}}}+\frac{1}{{{{|{OB}|}^2}}}=\frac{1}{¦Ñ_1^2}+\frac{1}{¦Ñ_2^2}=\frac{{{{cos}^2}¦È}}{4}+{sin^2}¦È+\frac{{{{sin}^2}¦È}}{4}+{cos^2}¦È=\frac{5}{4}$£®

µãÆÀ ±¾Ì⿼²éÈýÖÖ·½³ÌµÄ»¥»¯£¬¿¼²é¼«×ø±ê·½³ÌµÄÔËÓã¬ÊôÓÚÖеµÌ⣮

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

18£®ÒÑÖªÊýÁÐ{an}Âú×ãÌõ¼þ£ºa1=1£¬an+1=2an+1
£¨1£©ÇóÊýÁÐanµÄͨÏʽ
£¨2£©Áî${c_n}=\frac{2^n}{{{a_n}•{a_{n+1}}}}$¼ÇTn=c1+c2+c3+¡­+cn  ÇóTn£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

19£®ÒÑÖª¶¨ÒåÔÚ[0£¬+¡Þ£©Éϵĺ¯Êýf£¨x£©Âú×ãf£¨x+1£©=2f£¨x£©£¬µ±x¡Ê[0£¬1£©Ê±£¬f£¨x£©=-x2+x£¬Éèf£¨x£©ÔÚ[n-1£¬n£©ÉϵÄ×î´óֵΪ${a_n}£¨{n¡Ê{N^*}}£©$£¬Ôòa4=£¨¡¡¡¡£©
A£®2B£®1C£®$\frac{1}{16}$D£®$\frac{1}{32}$

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

16£®Ò»¸öÉÈÐεĻ¡³¤ÓëÃæ»ý¶¼ÊÇ3£¬Õâ¸öÉÈÐÎÖÐÐĽǵĻ¡¶ÈÊýÊÇ£¨¡¡¡¡£©
A£®$\frac{1}{2}$B£®1C£®$\frac{3}{2}$D£®2

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

3£®ÒÑÖª¸´ÊýzÂú×ã·½³Ìz•i=2-i£¬Ôò$\overline z$ÔÚ¸´Æ½ÃæÉ϶ÔÓ¦µãλÓÚ£¨¡¡¡¡£©
A£®µÚÒ»ÏóÏÞB£®µÚ¶þÏóÏÞC£®µÚÈýÏóÏÞD£®µÚËÄÏóÏÞ

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

13£®·½³Ìsin4x=sin2xÔÚ$£¨0£¬\frac{3}{2}¦Ð£©$ÉϵĽ⼯ÊÇ$\left\{{\frac{¦Ð}{6}£¬\frac{¦Ð}{2}£¬¦Ð£¬\frac{5¦Ð}{6}£¬\frac{7¦Ð}{6}}\right\}$£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

20£®ÒÑÖªm£¾2n£¬Ôòm+$\frac{4{n}^{2}-2mn+9}{m-2n}$µÄ×îСֵΪ£¨¡¡¡¡£©
A£®2B£®4C£®6D£®8

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

17£®ÉèÇúÏßx2=2yÓë¹ýÔ­µãµÄÖ±ÏßÏཻÓÚµãM£¬ÈôÖ±ÏßOMµÄÇãб½ÇΪ¦È£¬ÔòÏß¶ÎOMÓëÇúÏßΧ³ÉµÄ·â±ÕͼÐεÄÃæ»ýS£¨¦È£©µÄͼÏó´óÖÂÊÇ£¨¡¡¡¡£©
A£®B£®
C£®D£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

18£®Èçͼ£¬ÈýÀâÖùABC-A1B1C1ÖУ¬²àÃæAA1C1C¡Íµ×ÃæACB£¬AA1=A1C=AC=2$\sqrt{3}$£¬BC=$\sqrt{3}$£¬ÇÒA1C¡ÍBC£¬µãE£¬F·Ö±ðΪAB£¬A1C1µÄÖе㣮
£¨1£©ÇóÖ¤£ºBC¡ÍÆ½ÃæACA1£»
£¨2£©ÇóÖ¤£ºEF¡ÎÆ½ÃæBB1C1C£»
£¨3£©ÇóËÄÀâ×¶A1-BB1C1CµÄÌå»ý£®

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸