那是椭圆若是x^2/9-y^2/16=1则c^2=9+16=25c=5所以F(5,0)k=tanπ/4=1y=x-5代入16x^2-9(x-5)^2=1447x^2+90x-369=0x1+x2=-90/7,x1x2=-369/7(x1-x2)^2=(x1+x2)^2-4x1x2=18432/49(y1-y2)^2=[(x1-5)-(x2-5)]^2=(x1-x2)^2=1...