函数是中学数学的主轴内容,也是历年高考“经久不衰”的重点、难点和热点内容.各级各类考试命题者为了出好函数题而绞尽脑汁、挖苦心思,一些充满活力和魅力的函数题频频“闪亮登场”.下面给出两例,一例是关于闭函数问题,另一例是关于函数封闭问题,均颇具思考性和挑战性,值得同学 The function is the main content of middle school mathematics, and it is also the key, difficult and hot content of the previous college entrance examination “endlessness”. Various types of test propositions at all levels are racking their brains, diligently thinking, some energetic and Charm function frequency frequently “sound debut ”. Given two cases below, one case is about the closed function problem, and the other case is about function closure, both quite speculative and challenging, worthy of classmates