许多的学生对形如y=x2+4x-2,y=3x-4,y=lnx这样有具体对应法则的函数进行如探讨性质、求最值、画图形等事情都不会感到困难,但在面对的是没有具体对应法则的函数——抽象函数时,总感到难以解答。其实,大量的抽象函数都是以中学阶段所学的初等函数为背景抽象而得,解题时基本上不需要高等数学知识;它很强调对函数概念的正确理解,若是再运用一些技巧,则是容易解决此类问题。 Many students will find it difficult to explore functions with specific correspondence laws such as y = x2 + 4x-2, y = 3x-4, y = lnx, In the face of the law is not specific correspondence function - Abstract function, always feel difficult to answer. In fact, a large number of abstraction functions are abstracted from the elementary functions learned in the middle school stage. Basically, no knowledge of advanced mathematics is needed when solving problems; it emphasizes the correct understanding of the concept of functions. If we use some tricks again, Is easy to solve such problems.