原标题：A-level数学名师精讲 | 这类标题命题频率十分高。。
今日要解析的是一道会困扰学生一阵子的综合性标题，结合了指数函数和微分的问题。
在以往的考试中，命题频率十分高，但仍是有许多学生败给了这种类型题。
今日带咱们来处理一道这种类型题，而且给咱们伙儿一起来共享一下易错点和难点，让咱们今后遇到这种题能“手到擒来”。
真题解析 2017.10 C34 Question 3
本题(a)问是一道求值题，咱们咱们能够经过把t=0代入式子得值
依据examiner’s report:
Most knew that 3500 was the value required. The only mistakes were from those putting t=1 into
所以咱们要留意，当咱们要求the start value,咱们带入的t=0，而不是t=1。
本题(b)问是一道常考题型，这个首要考察的便是经过对数来处理指数函数power的取值规模。
第一步, write down inequality.
第二步，simplify both sides.
第三步，use logarithm to solve the inequality and simplify the answer.
依据Examiner’s report:
Most students gained the first two marks although occasionally BODMAS rule were misapplied, with students writing
, forfeiting these first two marks. Many were also successful in getting to t=30.516… hours, with various correct uses of logarithmic approaches. The most common error was getting from there to the correct number of hours and minutes, as required. Some rounded to 30.5 and obtained 30 hours and 30 minutes, losing the final mark. Some converted to 1831 minutes, losing the final mark. Occasionally an answer of 30 hours and 32 minutes was given, suggesting 100minutes in an hour.
这儿咱们应该留意几个点：
■ 对指数函数进行化简时，先对系数进行化简。
■ 经过对数来处理指数函数power的不等式时，当底数大于1，不等号不改动，当底数大于0而且小于1时，不等号要发作改动。
■ 最终的答案，需求按标题进行化简，不要算错了。
本题(c)问是一道常见的微分使用，要记住指数函数的微分一致。
第一步, differentiate the equation.
第二步, put the value into the deviated function.
■ 依据Examiner’s report：
The requirement to ‘Use Calculus’ was not followed by a significant minority who just worked out N when t was 8, or divided that number by 8, Those who correctly differentiated almost always got an acceptable answer. Those who incorrectly differentiated N, usually to , and then put t=8 could only gain one method mark for this part.
这儿咱们应该提示学生：
■ 对指数函数求导公式一定要把握，公式本不供给。
■ 要留意答案的保存要求，看标题详细阐明。
眼看圣诞将至，英国小伙伴们假日规划做得怎么样了？怎么使用圣诞假日高效提高AS数学成果？
圣诞假日教导课报起来，需求课程教导的请直接增加文末主页君微信了解哦，咱们的方针只要↓↓↓
报名咨询微信
| 英国住宿费 | 生活费
责任编辑：
