Question

动点P到点A(8,0)的距离是点B(2,0)的距离的2倍,求点的轨迹方程

Answer 1

设为P(x,y)

(x-8)^2+(y-0)^2=4(x-2)^2+4(y-0)^2

整理：

4x^2-16x+16+4y^3-x^2+16x-64-y^2=0

3x^2+2y^2=48

x^2/16+y^2/24=1

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