设双曲线x^2/a^2-y^2/b^2=1A、B点的坐标分别为A（x1,y1) ,B（-x1,-y1) P（x,y)是双曲线上上任意一点,x^2/a^2-y^2/b^2=1x1^2/a^2-y1^2/b^2=1两式相减得：b^2(x^2-x1^2)-a^2(y^2-y1^2)=0k(PA)=(y-y1)/(x-x1)k(PB)=(y+y...