在一次区公开课上,一位年轻教师上了一堂“函数性质在数列中的应用”公开课,本课主要研究了利用函数的最值和单调性来解决数列中的有关问题,课堂互动充分,多媒体应用得心应手,笔者收获不少.不过其中也有一点问题需要探讨.课堂教学片断例1已知数列{a_n}的通项公式a_n=n~2-κn,如果数列{a_n}为单调递增数列,则实数κ的取值范围是 In a district open class, a young teacher came to an agreement on the function of the nature of the series in the open class, the main study of the function of the most value and monotonicity to solve the problem in the series, the classroom Interactive full, multimedia applications handy, I gain a lot, but there are also some issues that need to be explored. Class teaching example 1 Known sequence {a_n} the general formula a_n = n ~ 2-κn, if the sequence {a_n} Ascending order of numbers, the range of the real number κ is