µÚ8ÕÂ µÚ6½Ú
Ò»¡¢Ñ¡ÔñÌâ
1£®ÒÑÖªA(2,5£¬£­6)£¬µãPÔÚyÖáÉÏ£¬|PA|£½7£¬ÔòµãPµÄ×ø±êÊÇ(¡¡¡¡)
A£®(0,8,0)¡¡¡¡¡¡¡¡ ¡¡¡¡ B£®(0,2,0)
C£®(0,8,0)»ò(0,2,0) D£®(0£¬£­8,0)
[´ð°¸]¡¡C
[½âÎö]¡¡µãPÔÚyÖáÉÏ£¬¿ÉÉèΪ(0£¬y,0)£¬
ÒòΪ|PA|£½7£¬A(2,5£¬£­6)£¬
ËùÒÔ22£«y£­52£«62£½7£¬½âµÃy£½2»ò8.
2£®ÉèµãBÊǵãA(2£¬£­3,5)¹ØÓÚxOy×ø±êÃæµÄ¶Ô³Æµã£¬Ôò|AB→|£½(¡¡¡¡)
A£®10¡¡¡¡¡¡ B.10¡¡¡¡¡¡ C.38¡¡¡¡¡¡ D£®38