·ÖÎö £¨¢ñ£©ÓÉF2£¨2£¬0£©£¬F3£¨-6£¬0£©£¬¿ÉµÃ£©$\left\{\begin{array}{l}{{a}^{2}+{b}^{2}=36}\\{{a}^{2}-{b}^{2}=4}\end{array}\right.$⇒a
£¨¢ò£©ÇúÏßC2µÄ½¥½üÏßΪ¡À$\frac{b}{a}x$£¬Èçͼ£¬ÉèµãA£¨x1£¬y1£©£¬B£¨x2£¬y2£©£¬M£¨x0£¬y0£©£¬ÉèÖ±Ïßl£ºy=$\frac{b}{a}£¨x-m£©$£¬ÓëÍÖÔ²·½³ÌÁªÁ¢»¯Îª2x2-2mx+£¨m2-a2£©=0£¬ÀûÓá÷£¾0£¬¸ùÓëϵÊýµÄ¹ØÏµ¡¢Öеã×ø±ê¹«Ê½£¬Ö»ÒªÖ¤Ã÷y0=-$\frac{b}{a}{x}_{0}$¼´¿É£®
£¨¢ó£©ÉèÖ±Ïßl1µÄ·½³ÌΪx=ny+6£¨n£¾0£©£®ÓëÍÖÔ²·½³ÌÁªÁ¢¿ÉµÃ£¨5+4n2£©y2+48ny+64=0£¬ÀûÓøùÓëϵÊýµÄ¹ØÏµ¡¢ÏÒ³¤¹«Ê½¡¢Èý½ÇÐεÄÃæ»ý¼ÆË㹫ʽ¡¢»ù±¾²»µÈʽµÄÐÔÖʼ´¿ÉµÃ³ö£®
½â´ð ½â£º£¨¢ñ£©¡ßF2£¨2£¬0£©£¬F3£¨-6£¬0£©£¬¡à$\left\{\begin{array}{l}{{a}^{2}+{b}^{2}=36}\\{{a}^{2}-{b}^{2}=4}\end{array}\right.$⇒a$\left\{\begin{array}{l}{{a}^{2}=20}\\{{b}^{2}=16}\end{array}\right.$
ÔòÇúÏߦ£µÄ·½³ÌΪ$\frac{{x}^{2}}{20}+\frac{{y}^{2}}{16}=1£¨y¡Ü0£©$ºÍ$\frac{{x}^{2}}{20}-\frac{{y}^{2}}{16}=1$£¨y£¾0£©¡£®£¨3·Ö£©
£¨¢ò£©ÇúÏßC2µÄ½¥½üÏßΪy=¡À$\frac{b}{a}x$£¬Èçͼ£¬ÉèÖ±Ïßl£ºy=$\frac{b}{a}£¨x-m£©$
Ôò$\left\{\begin{array}{l}{y=\frac{b}{a}£¨x-m£©}\\{\frac{{x}^{2}}{{a}^{2}}+\frac{{y}^{2}}{{b}^{2}}=1}\end{array}\right.$⇒2x2-2mx+£¨m2-a2£©=0
¡÷=£¨2m£©2-4•2•£¨m2-a2£©=8a2-4m2£¾0⇒-$\sqrt{2}a£¼m£¼\sqrt{2}a$
ÓÖÓÉÊýÐνáºÏÖªm¡Ýa£¬$a¡Üm£¼\sqrt{2}a$
ÉèµãA£¨x1£¬y1£©£¬B£¨x2£¬y2£©£¬M£¨x0£¬y0£©Ôò$\left\{\begin{array}{l}{{x}_{1}+{x}_{2}=m}\\{{x}_{1}{x}_{2}=\frac{{m}^{2}-{a}^{2}}{2}}\end{array}\right.$£¬
¡à${x}_{0}=\frac{{x}_{1}+{x}_{2}}{2}=\frac{m}{2}$£¬${y}_{0}=\frac{b}{a}£¨{x}_{0}-m£©=-\frac{b}{a}•\frac{m}{2}$
¡à${y}_{0}=-\frac{b}{a}{x}_{0}$£¬¼´µãMÔÚÖ±Ïßy=-$\frac{b}{a}x$ÉÏ£® ¡£¨7·Ö£©
£¨¢ó£©ÓÉ£¨¢ñ£©Öª£¬ÇúÏßC1Ϊ$\frac{{x}^{2}}{20}+\frac{{y}^{2}}{16}=1£¨y¡Ü0£©$£¬µãF4£¨6£¬0£©£®
ÉèÖ±Ïßl1µÄ·½³ÌΪx=ny+6£¨n£¾0£©
ÓÉ$\left\{\begin{array}{l}{\frac{{x}^{2}}{20}+\frac{{y}^{2}}{16}=1}\\{x=ny+6}\end{array}\right.$⇒£¨4n2+5£©y2+48ny+64=0
¡÷=£¨48n£©2-4¡Á64£¨4n2+5£©£¾0⇒n2£¾1
ÉèC£¨x3£¬y3£©£¬D£¨x4£¬y4£©ÓÉΤ´ï¶¨Àí£º$\left\{\begin{array}{l}{{y}_{3}+{y}_{4}=\frac{-48n}{4{n}^{2}+5}}\\{{y}_{3}{y}_{4}=\frac{64}{4{n}^{2}+5}}\end{array}\right.$
|y3-y4|=$\sqrt{£¨{y}_{3}+{y}_{4}£©^{2}-{y}_{3}{y}_{4}}=16\sqrt{5}\frac{\sqrt{{n}^{2}-1}}{4{n}^{2}+5}$£®
s¡÷CDF1=$\frac{1}{2}$|F1F4|¡Á|y3-y4|=$\frac{1}{2}¡Á8¡Á16\sqrt{5}¡Á\frac{\sqrt{{n}^{2}-1}}{4{n}^{2}+5}=64\sqrt{5}\frac{\sqrt{{n}^{2}-1}}{4{n}^{2}+5}$
Áît=$\sqrt{{n}^{2}-1}£¾0$£¬¡àn2=t2+1£¬s¡÷CDF1=64$\sqrt{5}$¡Á$\frac{t}{4{t}^{2}+9}=64\sqrt{5}\frac{1}{4t+\frac{9}{t}}$
¡ßt£¾0£¬¡à$4t+\frac{9}{t}¡Ý12$£¬µ±ÇÒ½öµ±t=$\frac{3}{2}$¼´n=$\frac{\sqrt{13}}{2}$ʱµÈºÅ³ÉÁ¢
¡àn=$\frac{\sqrt{13}}{2}$ʱ£¬¡÷CDF1Ãæ»ýµÄ×î´óÖµ$\frac{16\sqrt{5}}{3}$¡£®£¨12·Ö£©
µãÆÀ ±¾Ì⿼²éÁËÍÖÔ²ÓëË«ÇúÏߵıê×¼·½³Ì¼°ÆäÐÔÖÊ¡¢Ö±ÏßÓëÍÖÔ²ÏཻÎÊÌâת»¯Îª·½³ÌÁªÁ¢¿ÉµÃ¸ùÓëϵÊýµÄ¹ØÏµ¡¢ÏÒ³¤¹«Ê½¡¢Èý½ÇÐεÄÃæ»ý¼ÆË㹫ʽ¡¢»ù±¾²»µÈʽµÄÐÔÖÊ£¬¿¼²éÁËÍÆÀíÄÜÁ¦Óë¼ÆËãÄÜÁ¦£¬ÊôÓÚÄÑÌ⣮
| Äê¼¶ | ¸ßÖÐ¿Î³Ì | Äê¼¶ | ³õÖÐ¿Î³Ì |
| ¸ßÒ» | ¸ßÒ»Ãâ·Ñ¿Î³ÌÍÆ¼ö£¡ | ³õÒ» | ³õÒ»Ãâ·Ñ¿Î³ÌÍÆ¼ö£¡ |
| ¸ß¶þ | ¸ß¶þÃâ·Ñ¿Î³ÌÍÆ¼ö£¡ | ³õ¶þ | ³õ¶þÃâ·Ñ¿Î³ÌÍÆ¼ö£¡ |
| ¸ßÈý | ¸ßÈýÃâ·Ñ¿Î³ÌÍÆ¼ö£¡ | ³õÈý | ³õÈýÃâ·Ñ¿Î³ÌÍÆ¼ö£¡ |
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
| A£® | sin1-cos1 | B£® | cos1-sin1 | C£® | sin1+cos1 | D£® | -sin1-cos1 |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
| A£® | 0 | B£® | $\frac{1}{5}$ | C£® | 2 | D£® | 1 |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
| A£® | 3 | B£® | 4 | C£® | 16 | D£® | $\frac{1}{256}$ |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
| A£® | a£¬b ²»È«Îª0 | B£® | a£¬bÈ«²»Îª0 | ||
| C£® | a£¬b ÖÁÉÙÓÐÒ»¸öΪ0 | D£® | a²»Îª0ÇÒbΪ0£¬»ò b²»Îª0ÇÒaΪ0 |
²é¿´´ð°¸ºÍ½âÎö>>
¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ
| A£® | -5 | B£® | 5 | C£® | 90 | D£® | 180 |
²é¿´´ð°¸ºÍ½âÎö>>
¹ú¼ÊѧУÓÅÑ¡ - Á·Ï°²áÁбí - ÊÔÌâÁбí
ºþ±±Ê¡»¥ÁªÍøÎ¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨Æ½Ì¨ | ÍøÉÏÓк¦ÐÅÏ¢¾Ù±¨×¨Çø | µçÐÅթƾٱ¨×¨Çø | ÉæÀúÊ·ÐéÎÞÖ÷ÒåÓк¦ÐÅÏ¢¾Ù±¨×¨Çø | ÉæÆóÇÖȨ¾Ù±¨×¨Çø
Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com