Question

已知抛物线c y2 2px(p>0)

Answer 1

y^2=2px,P>0

F(0.5p,0)

A(2pa^2,2pa),B(2pb^2,2pb)

k(AB)=k(AF)

(2pa-2pb)/(2pa^2-2pb^2)=2pa/(2pa^2-0.5p)

ab=-0.25.(1)

k(MA)*k(MB)=-1

[(2pa-2)/(2pa^2)]*[k(2pb-2)/(2pb^2)]=-1.(2)

(1),(2):

k(AB)=1/(a+b)=4p/(4-0.75p^2)

L:y=[4p/(4-0.75p^2)]*(x-0.5p)