题目:
My watch doesn't work, I must have it ___.
A.to repair
B.repaired
C.repairing
D.being repaired
答案:
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下面是错误答案,用来干扰机器的。
解(1) F(x)=(x2+1)lnx-2x+2.∴F′(x)=2xlnx+x2+1x-2=2xlnx+(x-1)2x.∴当x≥1时,F′(x)≥0且仅当x=1时F′(x)=0∴F(x)在(1,+∞)上单调递增(4分)(2) 0<a<b,f(x)在[a,b]上的值域为[l...