1-[(x-1)/2]²≥ 0 怎么算

1-[(x-1)/2]²≥ 0 怎么算

1-[(x-1)/2]²≥ 0
[(x-1)/2]²≤1
(x-1)²/4≤1
(x-1)²≤4
-2≤x-1≤2
-1≤x≤3

答：
1-[(x-1)/2]²>=0
(x-1)² /4<=1
(x-1)²<=4
两边开平方：
-2<=x-1<=2
-1<=x<=3