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不等式是高中数学中的一个重要模块,也是高考的常考考点,其题型灵活多变、思维活跃,在解题时稍有不慎,就容易出错,下面举例说明常见的解题误区,供大家参考。一、忽视分类讨论致误例1若kx~2-6kx+(k+8)≥0恒成立,则k的取值范围是____。错解因为kx~2-6kx+(k+8)≥0恒成立,所以(■),得(■),即k的取值范围是(0,1]。剖析本题解法误认为不等式是一元二次不等式,忽视对k=0的讨论。
Inequality is an important module in high school mathematics, but also the college entrance examination often test sites, its flexible type of thinking, active thinking, in the solution of a slight mistake, it is easy to make mistakes, the following examples illustrate the common problem-solving errors for Everyone’s reference. First, ignore the taxonomy discussion error case 1 If kx ~ 2-6kx + (k + 8) ≥ 0 constant holds, then the range of k is ____. Since kx ~ 2-6kx + (k + 8) ≥0 holds true, (■) gives (■), that is, the range of k is (0,1). Analysis This problem solution mistaken for inequality is a binary The inequalities ignore the discussion of k = 0.