15£®¼×¡¢ÒÒÁ½È˲μÓijµçÊǪ́¾Ù°ìµÄ´ðÌâ´³¹ØÓÎÏ·£¬°´ÕÕ¹æÔò£º¼×ÏÈ´Ó6µÀ±¸Ñ¡ÌâÖÐÒ»´ÎÐÔ³éÈ¡3µÀÌâ¶ÀÁ¢×÷´ð£¬È»ºóÓÉÒһشðÊ£Óà3µÀÌ⣬ÿÈË´ð¶ÔÆäÖÐ2µÀÌâ¾ÍÍ£Ö¹´ðÌ⣬¼´´³¹Ø³É¹¦£®ÒÑÖªÔÚ6µÀ±¸Ñ¡ÌâÖУ¬¼×ÄÜ´ð¶ÔÆäÖеÄ4µÀÌ⣬ÒÒ´ð¶ÔÿµÀÌâµÄ¸ÅÂʶ¼ÊÇ$\frac{2}{3}$£®
£¨1£©Çó¼×´³¹Ø³É¹¦µÄ¸ÅÂÊ£»
£¨2£©Çó¼×¡¢ÒÒ¶þÈËÖÁÉÙÓÐÒ»ÈË´³¹Ø³É¹¦µÄ¸ÅÂÊ£»
£¨3£©ÉèÒÒ´ð¶ÔÌâÄ¿µÄ¸öÊýΪ¦Î£¬ÇóËæ»ú±äÁ¿¦ÎµÄ·Ö²¼ÁкÍÊýѧÆÚÍû£®

·ÖÎö £¨1£©¶Ô¼×ËùÑ¡µÄÌâÄ¿·ÖÀàÌÖÂÛ£¬ÀûÓÃÏ໥¶ÀÁ¢Ê¼þµÄ¸ÅÂʼÆË㹫ʽ¼´¿ÉµÃ³ö¼×´³¹Ø³É¹¦µÄ¸ÅÂÊ£®
£¨2£©Éè¼×¡¢ÒÒ´³¹Ø³É¹¦·Ö±ðΪʼþA¡¢B£¬ÔòP£¨$\overline{A}$£©=$\frac{{∁}_{4}^{1}{∁}_{2}^{2}}{{∁}_{6}^{3}}$£¬P£¨$\overline{B}$£©=$£¨1-\frac{2}{3}£©^{3}+{∁}_{3}^{2}¡Á\frac{2}{3}¡Á£¨1-\frac{2}{3}£©^{2}$£¬¿ÉµÃ¼×¡¢ÒÒÖÁÉÙÓÐÒ»ÈË´³¹Ø³É¹¦µÄ¸ÅÂÊÊÇ1-P£¨$\overline{A}\overline{B}$£©=1-$P£¨\overline{A}£©P£¨\overline{B}£©$£®
£¨3£©ÓÉÌâÒâ¿ÉµÃ£º¦Î¡«B$£¨3£¬\frac{2}{3}£©$£¬P£¨¦Î=k£©=${∁}_{3}^{k}£¨\frac{2}{3}£©^{k}£¨\frac{1}{3}£©^{3-k}$£¬¼´¿ÉµÃ³ö£®

½â´ð ½â£º£¨1£©¼×´³¹Ø³É¹¦µÄ¸ÅÂÊP=$\frac{{∁}_{4}^{1}}{{∁}_{6}^{1}}¡Á\frac{{∁}_{3}^{1}}{{∁}_{5}^{1}}$+$\frac{{∁}_{4}^{1}}{{∁}_{6}^{1}}¡Á\frac{{∁}_{2}^{1}}{{∁}_{5}^{1}}¡Á\frac{{∁}_{3}^{1}}{{∁}_{4}^{1}}$+$\frac{{∁}_{2}^{1}}{{∁}_{6}^{1}}¡Á\frac{{∁}_{4}^{2}}{{∁}_{5}^{2}}$=$\frac{4}{5}$£®
£¨2£©Éè¼×¡¢ÒÒ´³¹Ø³É¹¦·Ö±ðΪʼþA¡¢B£¬
ÔòP£¨$\overline{A}$£©=$\frac{{∁}_{4}^{1}{∁}_{2}^{2}}{{∁}_{6}^{3}}$=$\frac{1}{5}$£¬P£¨$\overline{B}$£©=$£¨1-\frac{2}{3}£©^{3}+{∁}_{3}^{2}¡Á\frac{2}{3}¡Á£¨1-\frac{2}{3}£©^{2}$=$\frac{7}{27}$£¬
Ôò¼×¡¢ÒÒÖÁÉÙÓÐÒ»ÈË´³¹Ø³É¹¦µÄ¸ÅÂÊÊÇ1-P£¨$\overline{A}\overline{B}$£©=1-$P£¨\overline{A}£©P£¨\overline{B}£©$=1-$\frac{1}{5}¡Á\frac{7}{27}$=$\frac{128}{135}$£®
£¨3£©ÓÉÌâÒâ¿ÉµÃ£º¦Î¡«B$£¨3£¬\frac{2}{3}£©$£¬P£¨¦Î=k£©=${∁}_{3}^{k}£¨\frac{2}{3}£©^{k}£¨\frac{1}{3}£©^{3-k}$£¬

 ¦Î 0 1 2 3
 P $\frac{1}{27}$ $\frac{6}{27}$ $\frac{12}{27}$ $\frac{8}{27}$
E£¨¦Î£©=$3¡Á\frac{2}{3}$=2£®

µãÆÀ ±¾Ì⿼²éÁËÏ໥¶ÀÁ¢Óë¶ÔÁ¢Ê¼þµÄ¸ÅÂʼÆË㹫ʽ¡¢¶þÏî·Ö²¼ÁеÄÐÔÖʼ°ÆäÊýѧÆÚÍû£¬¿¼²éÁËÍÆÀíÄÜÁ¦Óë¼ÆËãÄÜÁ¦£¬ÊôÓÚÖеµÌ⣮

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

5£®ÒÑÖª·½³Ìx3+ax2+bx+c=0£¨a£¬b£¬c¡ÊR£©£®
£¨1£©Éèa=b=4£¬·½³ÌÓÐÈý¸ö²»Í¬Êµ¸ù£¬ÇócµÄȡֵ·¶Î§£»
£¨2£©ÇóÖ¤£ºa2-3b£¾0ÊÇ·½³ÌÓÐÈý¸ö²»Í¬Êµ¸ùµÄ±ØÒª²»³ä·ÖÌõ¼þ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

6£®ÒÑÖªtan£¨x+$\frac{¦Ð}{4}$£©=3£¬ÔòsinxcosxµÄÖµÊÇ$\frac{2}{5}$£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

3£®Ä³¹¤³§Éú²úijÖÖ²úÆ·£¬Ã¿Èյijɱ¾C£¨µ¥Î»£ºÍòÔª£©ÓëÈÕ²úÁ¿x£¨µ¥Î»£º¶Ö£©Âú×㺯Êý¹ØÏµC=3+x£¬Ã¿ÈÕµÄÏúÊÛS£¨µ¥Î»£ºÍòÔª£©ÓëÈÕ²úÁ¿xµÄº¯Êý¹ØÏµÊ½ÎªS=$\left\{\begin{array}{l}{3x+5+\frac{k}{x-8}£¬0£¼x£¼6}\\{14£¬x¡Ý6}\end{array}\right.$£®ÒÑ֪ÿÈÕµÄÀûÈóL=S-C£¬ÇÒµ±x=2ʱ£¬L=3£®
£¨¢ñ£©ÇókµÄÖµ£»
£¨¢ò£©µ±ÈÕ²úÁ¿Îª¶àÉÙ¶Öʱ£¬Ã¿ÈÕµÄÀûÈó¿ÉÒÔ´ïµ½×î´ó£¬²¢Çó´Ë×î´óÖµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

10£®ÔĶÁÈçͼµÄ³ÌÐò¿òͼ£¬ÔËÐÐÏàÓ¦µÄ³ÌÐò£¬ÔòÊä³ösµÄֵΪ£¨¡¡¡¡£©
A£®-6B£®6C£®-5D£®5

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

20£®ÉèÊýÁÐ{an}µÄǰnÏîºÍΪSn£¬Èô$\frac{1}{2}¡Ü\frac{{{a_{n+1}}}}{a_n}¡Ü2$£¨n¡ÊN*£©£¬Ôò³Æ{an}ÊÇ¡°½ôÃÜÊýÁС±£»
£¨1£©Èôa1=1£¬${a_2}=\frac{3}{2}$£¬a3=x£¬a4=4£¬ÇóxµÄȡֵ·¶Î§£»
£¨2£©Èô{an}ΪµÈ²îÊýÁУ¬Ê×Ïîa1£¬¹«²îd£¬ÇÒ0£¼d¡Üa1£¬ÅжÏ{an}ÊÇ·ñΪ¡°½ôÃÜÊýÁС±£»
£¨3£©ÉèÊýÁÐ{an}Êǹ«±ÈΪqµÄµÈ±ÈÊýÁУ¬ÈôÊýÁÐ{an}Óë{Sn}¶¼ÊÇ¡°½ôÃÜÊýÁС±£¬ÇóqµÄȡֵ·¶Î§£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

7£®Ä³Ð£¸ßÈý£¨1£©°àÈ«ÌåÅ®ÉúµÄÒ»´ÎÊýѧ²âÊԳɼ¨µÄ¾¥Ò¶Í¼ºÍƵÂÊ·Ö²¼Ö±·½Í¼¶¼Êܵ½²»Í¬³Ì¶ÈµÄÆÆ»µ£¬µ«¿É¼û²¿·ÖÈçͼËùʾ£¬¾Ý´Ë½â´ðÈçÏÂÎÊÌ⣺
£¨1£©Çó·ÖÊýÔÚ[80£¬90£©ÄÚµÄÅ®ÉúÈËÊý£¬²¢¼ÆËãÆµÂÊ·Ö²¼Ö±·½Í¼ÖÐ[80£¬90£©¶ÔÓ¦µÄ¾ØÐεĸߣ»
£¨2£©ÒÔÕâ¸ö°àµÄÑù±¾Êý¾ÝÀ´¹À¼ÆÈ«Ð£µÄ×ÜÌåÊý¾Ý£¬Èô´ÓȫУ¸ßÈýÅ®ÉúÖÐÈÎÑ¡ÈýÈË£¬ÉèX±íʾÊýѧ³É¼¨²»µÍÓÚ80·ÖµÄѧÉúÈËÊý£¬ÇóXµÄ·Ö²¼ÁкÍÊýѧÆÚÍû£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

4£®ÒÑÖªÊýÁÐ{an}µÄǰnÏîºÍΪSn£¬ÇÒ3Sn=2¡Á4n-2£¬n¡ÊN*£®
£¨I£©ÇóÊýÁÐ{an}µÄͨÏʽan£»
£¨II£©ÉèÊýÁÐ{bn}Âú×ãbn=log2an£¬ÇóTn=$\frac{1}{{b}_{1}{b}_{2}}$+$\frac{1}{{b}_{2}{b}_{3}}$+¡­+$\frac{1}{{b}_{n}{b}_{n+1}}$µÄ±í´ïʽ£¨Óú¬nµÄ´úÊýʽ±íʾ£©£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

5£®¸ø³öÏÂÁк¯Êý¢Ùy=xcosx¢Úy=sin2x¢Ûy=|x2-x|¢Üy=ex-e-x£¬ÆäÖÐÊÇÆæº¯ÊýµÄÊÇ£¨¡¡¡¡£©
A£®¢Ù¢ÚB£®¢Ù¢ÜC£®¢Ú¢ÜD£®¢Û¢Ü

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸