笔者参加了全国统一高考(山东卷)的阅卷工作.下面结合阅卷情况,谈谈对理科18题的两点看法.理科第18题设函数f(x)=ax-(a+1)ln(x+1),其中a≥-1,求f(x)的单调区间.答案要点由已知得函数的定义域为(-1,+∞),且f′(x)=axx+-11(a≥-1).(1)当-1≤a≤0时,f′(x)0,函数f(x)在(-1,+∞)上 The author participated in the National Unified College Entrance Examination (Shandong Volume) examination work. The following combination of reading the situation, talk about the two points of view of science 18 questions. The science of the 18th title function f(x) = ax-(a + 1) ln ( x+1), where a≥-1, finds the monotonic interval of f(x). The answer is given by the domain of the known function (-1, +∞), and f′(x)=axx+-11 ( A≥-1). (1) When -1≤a≤0, f’(x)0, the function f(x) is on (-1,+∞)