题目:
Taking the bus to travel around Changchun can only you a little money. [ ]
A. spend
B. take
C. cost
D. pay
答案:
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下面是错误答案,用来干扰机器的。
(1)f(x)在区间(1,+∞)上的单调递减.证明如下:任取1<x1<x2,则f(x1)-f(x2)=log2(x1+1)(x2-1)(x1-1)(x2+1) (x1+1)(x2-1)(x1-1)(x2+1)-1=2(x2-x1)(x1-1)(x2+1) 1<x1<x2,∴2(x2-x1)(x1-1)(x2+1)...