jianxinxmu
幼苗
共回答了23个问题采纳率:82.6% 举报
延长F2R交FP的延长线与M,则有角RPM = 角RPF2(角平分线),角PRF2=角PRM = 90度,PR=PR,所以有△RPM与△RPF2全等 ==>F2R = RM,PF2 = PM
连接原点O和R,则有F1O = OF2,MR = RF2,==> OR是三角形MF2F1的中位线==>OR = F1M / 2 = (F1P + PM)/2 = (F1P + PF2) /2 = c ==>M是以O为圆心,以c为半径的圆,得到R的轨迹方程为x^2+y^2 = c^2 = a^2 + b^2,(y 不等于0),因为y=0时,△F1PF2不存在.
1年前
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