26.對(duì)于在平面直角坐標(biāo)系xOy中的兩點(diǎn)P(x
1,y
1)和Q(x
2,0),給出如下定義:若OP=3-x
2(0<x
2≤1),則稱點(diǎn)P為點(diǎn)Q的依附點(diǎn).
(1)當(dāng)x
2=1時(shí),在點(diǎn)P
1(2,0),P
2(-1,
),P
3(1,-1)中,點(diǎn)Q的依附點(diǎn)是
;
(2)若直線y=
x上的點(diǎn)P是點(diǎn)Q的依附點(diǎn),求點(diǎn)P橫坐標(biāo)的取值范圍;
(3)若直線y=-x+m上存在點(diǎn)Q的依附點(diǎn),直接寫出m的取值范圍.