|x-1|=根号(1-(y-1)^2)(x-1)^2=1-(y-1)^2 1-(y-1)^2≥0(x-1)^2+(y-1)^2=1 (y-1)^2≤1(x-1)^2+(y-1)^2=1 0≤y≤2表示以(1,1)为圆心,1为半径的圆答案说是两个半圆的话,答案错了.做出那个答案的人把我上面过程里的≥写...