已知抛物线y^2=2px的焦点为F点p1(x1,y1)p2(x2,y2)p3(x3,y3)在抛物线上且2x2=x1+x3
问题描述:
已知抛物线y^2=2px的焦点为F点p1(x1,y1)p2(x2,y2)p3(x3,y3)在抛物线上且2x2=x1+x3
答
是这题吗?已知抛物线y2=2px(p>0)的焦点为F,点P1(x1,y1),P2(x2,y2),P3(x3,y3)在抛物线上,且2x2=x1+x3,则有( C ) A.|FP1|+|FP2|=|FP3| B.|FP1|^2+|FP2|^2=|FP3|^2 C.2|FP2|=|FP1|+|FP3| D.|FP2|^2=|FP1|·...