问题
选择题
若-4＜x＜1，则
|
答案
变形可得
=x2-2x+2 2x-2
=x2-2x+1+1 2(x-1)
=(x-1)2+1 2(x-1)
+x-1 2 1 2(x-1)
∵-4＜x＜1，∴-5＜x-1＜0，
故原式=
+x-1 2
=-[-1 2(x-1)
+x-1 2
]≤-21 -2(x-1)
=-1-
•x-1 2 1 -2(x-1)
当且仅当-
=x-1 2
，即x=0时，取等号，1 -2(x-1)
故选C