4£®¾­¹ýÅ×ÎïÏßy2=2px£¨p£¾0£©ÍâÒ»µãA£¨-2£¬-4£©µÄÖ±Ïßl£º$\left\{\begin{array}{l}{x=-2+\frac{\sqrt{2}}{2}t}\\{y=-4+\frac{\sqrt{2}}{2}t}\\{\;}\end{array}\right.$£¨tΪ²ÎÊý£¬t¡ÊR£©ÓëÅ×ÎïÏß·Ö±ð½»ÓÚM1£¬M2Á½µã£¬ÇÒ|AM1|¡¢|M1M2|£¬|AM2|³ÉµÈ±ÈÊýÁУ®
£¨1£©°ÑÖ±ÏßlµÄ²ÎÊý·½³Ì»¯ÎªÆÕͨ·½³Ì£»
£¨2£©ÇópµÄÖµ¼°Ïß¶ÎM1M2µÄ³¤¶È£®

·ÖÎö £¨1£©½«²ÎÊý·½³ÌÁ½Ê½Ïà¼õ¼´¿ÉÏû²ÎÊýµÃµ½lµÄÆÕͨ·½³Ì£»
£¨2£©°ÑÖ±ÏßlµÄ²ÎÊý·½³Ì´úÈëÅ×ÎïÏß·½³Ì£¬ÀûÓøùÓëϵÊýµÄ¹ØÏµ¼°²ÎÊýµÄ¼¸ºÎÒâÒåµÃ³ö|AM1|¡¢|M1M2|£¬|AM2|£¬¸ù¾ÝµÈ±ÈÊýÁÐÁгö·½³Ì½â³öp£®

½â´ð ½â£º£¨1£©½«²ÎÊý·½³ÌÁ½Ê½Ïà¼õµÃx-y=2£¬¼´x-y-2=0£®
¡àÖ±ÏßlµÄÆÕͨ·½³ÌΪx-y-2=0£®
£¨2£©°Ñ£º$\left\{\begin{array}{l}{x=-2+\frac{\sqrt{2}}{2}t}\\{y=-4+\frac{\sqrt{2}}{2}t}\\{\;}\end{array}\right.$£¨tΪ²ÎÊý£©´úÈëy2=2pxµÃ£ºt2-2$\sqrt{2}$£¨4+p£©t+8£¨4+p£©=0£¬
ÉèM1£¬M2¶ÔÓڵIJÎÊý·Ö±ðΪt1£¬t2£®Ôòt1+t2=2$\sqrt{2}$£¨4+p£©£¬t1t2=8£¨4+p£©£®
¡ß|AM1|¡¢|M1M2|£¬|AM2|³ÉµÈ±ÈÊýÁУ¬
¡à£¨t1-t2£©2=|t1||t2|=t1t2£®
¡à£¨t1+t2£©2=5t1t2£®¼´8£¨4+p£©2=40£¨4+p£©£®½âµÃp=1»òp=-4£¨Éᣩ£®
¡àt1t2=40£®
¡à|M1M2|=|t1-t2|=$\sqrt{{t}_{1}{t}_{2}}$=$\sqrt{40}$=2$\sqrt{10}$£®

µãÆÀ ±¾Ì⿼²éÁ˲ÎÊý·½³ÌÓëÆÕͨ·½³ÌµÄת»¯£¬²ÎÊýµÄ¼¸ºÎÒâÒå¼°Ó¦Óã¬ÊôÓÚÔÚÖеµÌ⣮

Á·Ï°²áϵÁдð°¸
Ïà¹ØÏ°Ìâ

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

14£®ÒÑÖªÅ×ÎïÏßC£ºy2=8xµÄ½¹µãΪF£¬×¼ÏßΪl£¬PÊÇlÉÏÒ»µã£¬QÊÇÖ±ÏßPFÓëCµÄÒ»¸ö½»µã£¬Èô$\overrightarrow{FP}$=4$\overrightarrow{FQ}$£¬Ôò|QF|=£¨¡¡¡¡£©
A£®3B£®$\frac{5}{2}$C£®$\frac{7}{2}$D£®$\frac{3}{2}$

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

15£®ÒÑÖª²»µÈʽ£¨ax+3£©£¨x2-b£©¡Ü0¶ÔÈÎÒâx¡Ê£¨0£¬+¡Þ£©ºã³ÉÁ¢£¬ÆäÖÐa£¬bÊÇÕûÊý£¬Ôòa+bµÄȡֵµÄ¼¯ºÏΪ{-2£¬8}£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

12£®ÓÐÒ»¸ö³¤Îª10Ã׵ľ°ôб²åÔÚµØÃæÉÏ£¬µãPÊǵØÃæÄÚµÄÒ»¸ö¶¯µã£¬ÈôµãPÓëľ°ôµÄÁ½¸ö¶Ëµã¹¹³ÉµÄÈý½ÇÐÎÃæ»ýΪ¶¨Öµ£¬ÔòµãPµÄ¹ì¼£Îª£¨¡¡¡¡£©
A£®ÍÖÔ²B£®Ô²C£®Á½ÌõƽµÈÖ±ÏßD£®Ë«ÇúÏß

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

19£®ÒÑÖªÒ»¸öËã·¨£¬ÆäÁ÷³ÌͼÈçÏ£¬ÔòÊäŒçµÄ½á¹ûÊÇ£¨¡¡¡¡£©
A£®8B£®9C£®10D£®11

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

9£®ÉèÊýÁÐ{an}µÄ¸÷Ïî¾ùΪÕýÊý£¬ÆäǰnÏîºÍSnÂú×ãSn=$\frac{1}{6}$£¨${a_n}^2$+3an-4£©£¬ÔòSn=$\frac{3}{2}$n2+$\frac{5}{2}n$£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÌî¿ÕÌâ

16£®ÔÚ¡÷ABCÖУ¬sinA£ºsinB£ºsinC=4£º5£º7£¬µãMΪBCµÄÖе㣬AM=$\sqrt{11}$£¬ÔòAC=$\frac{{5\sqrt{3}}}{3}$£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£º½â´ðÌâ

13£®ÒÑÖª¡÷ABCµÄÃæ»ýΪS£¬ÇÒ$\frac{{\sqrt{3}}}{2}$$\overrightarrow{AB}$•$\overrightarrow{AC}$=S£¬|${\overrightarrow{AC}$-$\overrightarrow{AB}}$|=3£®
£¨¢ñ£©Èôf£¨x£©=2cos£¨¦Øx+B£©£¨¦Ø£¾0£©µÄͼÏóÓëÖ±Ïßy=2ÏàÁÚÁ½¸ö½»µã¼äµÄ×î¶Ì¾àÀëΪ2£¬ÇÒf£¨$\frac{1}{6}$£©=1£¬Çó¡÷ABCµÄÃæ»ýS£»
£¨¢ò£©ÇóS+3$\sqrt{3}$cosBcosCµÄ×î´óÖµ£®

²é¿´´ð°¸ºÍ½âÎö>>

¿ÆÄ¿£º¸ßÖÐÊýѧ À´Ô´£º ÌâÐÍ£ºÑ¡ÔñÌâ

14£®ÒÑÖªcos£¨¦Á-$\frac{¦Ð}{4}$£©=$\frac{\sqrt{3}}{2}$£¬Ôòsin2¦Á=£¨¡¡¡¡£©
A£®$\frac{1}{2}$B£®$\frac{\sqrt{3}}{2}$C£®-$\frac{1}{2}$D£®-$\frac{\sqrt{3}}{2}$

²é¿´´ð°¸ºÍ½âÎö>>

ͬ²½Á·Ï°²á´ð°¸