ÌâÄ¿ÄÚÈÝ
ÎÒÃÇ°ÑÀëÐÄÂÊΪe£½µÄË«ÇúÏß(a>0£¬b>0)³ÆΪ»Æ½ðË«ÇúÏߣ®Èçͼ£¬
ÊÇË«ÇúÏßµÄʵÖᶥµã£¬
ÊÇÐéÖáµÄ¶¥µã£¬
ÊÇ×óÓÒ½¹µã£¬
ÔÚË«ÇúÏßÉÏÇÒ¹ýÓÒ½¹µã
£¬²¢ÇÒ
Öᣬ¸ø³öÒÔϼ¸¸ö˵·¨£º
¢ÙË«ÇúÏßx2££½1ÊǻƽðË«ÇúÏߣ»
¢ÚÈôb2£½ac£¬Ôò¸ÃË«ÇúÏßÊǻƽðË«ÇúÏߣ»
¢ÛÈçͼ£¬Èô¡ÏF1B1A2£½90¡ã£¬Ôò¸ÃË«ÇúÏßÊǻƽðË«ÇúÏߣ»
¢ÜÈçͼ£¬Èô¡ÏMON£½90¡ã£¬Ôò¸ÃË«ÇúÏßÊǻƽðË«ÇúÏߣ®
ÆäÖÐÕýÈ·µÄÊÇ(¡¡¡¡)
A£®¢Ù¢Ú¢Ü | B£®¢Ù¢Ú¢Û | C£®¢Ú¢Û¢Ü | D£®¢Ù¢Ú¢Û¢Ü |
D
½âÎöÊÔÌâ·ÖÎö£º¢ÙÓÉË«ÇúÏßx2££½1£¬¿ÉµÃÀëÐÄÂÊe=
£¬¼´¿ÉÅжϳö¸ÃË«ÇúÏßÊÇ·ñÊǻƽðË«ÇúÏߣ»
¢ÚÓÉb2=ac£¬¿ÉµÃc2-a2-ac=0£¬»¯Îªe2-e-1=0£¬ÓÖe£¾1£¬½âµÃe£¬¼´¿ÉÅжϳö¸ÃË«ÇúÏßÊÇ·ñÊǻƽðË«ÇúÏߣ»
¢ÛÈçͼ£¬ÓÉ¡ÏF1B1A2=90¡ã£¬¿ÉµÃ|B1F1|2+|B1A2|2£½|F1A2|2£¬¿ÉµÃb2+c2+b2+a2=£¨a+c£©2£¬»¯Îªc2-ac-a2=0£¬¼´¿ÉÅжϳö¸ÃË«ÇúÏßÊÇ·ñÊǻƽðË«ÇúÏߣ»
¢ÜÈçͼ£¬ÓÉ¡ÏMON=90¡ã£¬¿ÉµÃMN¡ÍxÖᣬ|MF2|£½£¬¿ÉµÃ¡÷MOF2ÊǵÈÑüÖ±½ÇÈý½ÇÐΣ¬µÃµ½c=
£¬¼´¿ÉÅжϳö¸ÃË«ÇúÏßÊÇ·ñÊǻƽðË«ÇúÏߣ®
¿¼µã£ºÔ²×¶ÇúÏßµÄ×ÛºÏÓ¦ÓÃ.
![](http://thumb2018.1010pic.com/images/loading.gif)