论文部分内容阅读
在2009年高考中,很多省市考到恒成立问题,恒成立问题是高考考查的热点,本文以2009年高考题阐述求解恒成立问题。以提高学生思维能力与解题能力。一子集法在解题过程中,利用集合之间的包含关系得出恒成立的条件,从而使问题得以解决。例1(2009年北京理·18)设函数f(x)=xe~(kx)(k≠0)。(Ⅰ)求曲线y=f(x)在点(0,f(0))处的切线方程;
In the college entrance examination in 2009, many provinces and cities to test the establishment of a permanent problem, the permanent establishment of the college entrance examination examination is the hot spot, this article to explain the 2009 college entrance examination to solve the problem of permanent establishment. To improve students’ ability to think and solve problems. A subset of the law in the process of solving problems, the use of the inclusion relations between the collection of conditions derived from constant, so that the problem can be solved. Example 1 (2009 Beijing Li 18) Let f (x) = xe ~ (kx) (k ≠ 0). (Ⅰ) Find the tangent equation of the curve y = f (x) at the point (0, f (0));