设P(2t,t)
则|PA|Λ2+|PB|Λ2
=(2t-1)²+(t-1)²+(2t-2)²+(t-2)²
=10t²-18t+10
∴ 对称轴是t=9/10
即t=9/10时,|PA|Λ2+|PB|Λ2有最小值,
∴ P点坐标是(9/5,9/10)
设P(2t,t)
则|PA|Λ2+|PB|Λ2
=(2t-1)²+(t-1)²+(2t-2)²+(t-2)²
=10t²-18t+10
∴ 对称轴是t=9/10
即t=9/10时,|PA|Λ2+|PB|Λ2有最小值,
∴ P点坐标是(9/5,9/10)