ÌâÄ¿ÄÚÈÝ

£¨2008•ÆÖ¶«ÐÂÇø¶þÄ££©ÎÊÌ⣺¹ýµãM£¨2£¬1£©×÷һбÂÊΪ1µÄÖ±Ïß½»Å×ÎïÏßy2=2px£¨p£¾0£©ÓÚ²»Í¬µÄÁ½µãA£¬B£¬ÇÒµãMΪABµÄÖе㣬ÇópµÄÖµ£®ÇëÔĶÁijͬѧµÄÎÊÌâ½â´ð¹ý³Ì£º
½â£ºÉèA£¨x1£¬y1£©£¬B£¨x2£¬y2£©£¬Ôòy12=2px1£¬y22=2px2£¬Á½Ê½Ïà¼õ£¬µÃ£¨y1-y2£©£¨y1+y2£©=2p£¨x1-x2£©£®ÓÖkAB=
y1-y2x1-x2
=1
£¬y1+y2=2£¬Òò´Ëp=1£®
²¢¸ø³öµ±µãMµÄ×ø±ê¸ÄΪ£¨2£¬m£©£¨m£¾0£©Ê±£¬ÄãÈÏΪÕýÈ·µÄ½áÂÛ£º
p=m£¨0£¼m£¼4£©
p=m£¨0£¼m£¼4£©
£®
·ÖÎö£ºÉèA£¨x1£¬y1£©£¬B£¨x2£¬y2£©£¬Ôòy12=2px1£¬y22=2px2£¬Á½Ê½Ïà¼õ£¬µÃ£¨y1-y2£©£¨y1+y2£©=2p£¨x1-x2£©£®ÓÖkAB=
y1-y2
x1-x2
=1
£¬y1+y2=2mËùÒÔp=m£¬½«Ö±Ïß·½³ÌÓëÅ×ÎïÏߵķ½³ÌÁªÁ¢£¬Åбðʽ´óÓÚ0Çó³ömµÄ·¶Î§£®
½â´ð£º½â£ºÉèA£¨x1£¬y1£©£¬B£¨x2£¬y2£©£¬
Ôòy12=2px1£¬y22=2px2£¬
Á½Ê½Ïà¼õ£¬µÃ£¨y1-y2£©£¨y1+y2£©=2p£¨x1-x2£©£®
ÓÖkAB=
y1-y2
x1-x2
=1
£¬y1+y2=2m
ËùÒÔ1=
2p
2m

ËùÒÔp=m
ÒòΪ
y2=2px
y-m=x-2
ÏûÈ¥xµÃ
y2-2py+2pm-4p=0
¼´y2-2my+2m2-4m=0
¡÷=4m2-4£¨2m2-4m£©£¾0
½âµÃ0£¼m£¼4
¹Ê´ð°¸Îª£ºp=m£¨0£¼m£¼4£©
µãÆÀ£º½â¾öÖ±ÏßÓëԲ׶ÇúÏßÏཻÓйØÏÒÖеãµÄÎÊÌ⣬³£ÀûÓõã²î·¨À´½â¾ö£¬µ«×¢ÒâÐèÒª½«Ö±Ïߵķ½³ÌÓëԲ׶ÇúÏߵķ½³ÌÁªÁ¢£¬Åбðʽ´óÓÚ0£®
Á·Ï°²áϵÁдð°¸
Ïà¹ØÌâÄ¿

Î¥·¨ºÍ²»Á¼ÐÅÏ¢¾Ù±¨µç»°£º027-86699610 ¾Ù±¨ÓÊÏ䣺58377363@163.com

¾«Ó¢¼Ò½ÌÍø