Question

救命:一道轨迹方程数学题已知平面上有两定点A,B,|AB|=2a,(a>0),平面上一动点到A,B两点距离之比为2:1,

Answer 1

设定点A（-a,0）B（-a,0）

点M（x,y）依定义有|MA|/|MB|=2/1

--->|MA|=2|MB|

--->|MA|^2=4|MB|^2

--->(x+a)^2+y^2=4[(x-a)^2+y^2]

--->3x^2+3y^2-10x+3a^2=0

--->x^2+y^2-10x/3+a^2=0