如图tan∠MAB=y/(x+2).tan∠MBA=y/(1-x)
∠MBA=2∠MAB.
∴y/(1-x)=[2y/(x+2)]/[1-(y/(x+2))²].
3x²-y²+4x=0.
点M的轨迹方程:x=√[(y²/3)+4/9]-2/3.
(双曲线(x+2/3)²-y²/3=4/9的右支)
如图tan∠MAB=y/(x+2).tan∠MBA=y/(1-x)
∠MBA=2∠MAB.
∴y/(1-x)=[2y/(x+2)]/[1-(y/(x+2))²].
3x²-y²+4x=0.
点M的轨迹方程:x=√[(y²/3)+4/9]-2/3.
(双曲线(x+2/3)²-y²/3=4/9的右支)