P(x,y),A(-5,0),B(5,0),rA=7,rB=1
PA=( (x+5)^2+y^2 )^0.5
PB=( (x-5)^2+y^2 )^0.5
PA-rA=PB-rB
( (x+5)^2+y^2 )^0.5 - 7 =( (x-5)^2+y^2 )^0.5 - 1
所以轨迹方程为:16x^2-9y^2=144
P(x,y),A(-5,0),B(5,0),rA=7,rB=1
PA=( (x+5)^2+y^2 )^0.5
PB=( (x-5)^2+y^2 )^0.5
PA-rA=PB-rB
( (x+5)^2+y^2 )^0.5 - 7 =( (x-5)^2+y^2 )^0.5 - 1
所以轨迹方程为:16x^2-9y^2=144