我来试试吧.
设弦的端点A(x1,y1) B(x2,y2)则
y1^2=2px1 y2^2=2px2
(y1-y2)(y1+y2)=2p(x1-x2)
则k= (y1-y2)/(x1-x2)=2p/(y1+y2)=2
由题,y1+y2=2*1=2
故p=2有道理有道理谢谢啦呵呵 能帮到你就好···