一、“说三”———说说蕴含于极限问题之中的三种数学思想1.化归思想化归思想作用于极限问题中,主要表现于把不同类型的极限运算题转化到一种类型的问题.如在计算“∞-∞”型、“00”型等极限运算题时,常采用必要的变形手段把它们转化成“∞∞”或其它易求的类型,利用这些类型 First, “say three” --- talk about the three kinds of mathematical ideas contained in the limits of the problem 1. The idea of ​​ideology goes into the limit problem, mainly in the conversion of different types of limit calculation problems to a Type problems, such as calculation of “∞-∞” type, “00” type limit calculation problems, often using the necessary transformation means to convert them into “∞∞” or other types of easy-to-use, use these types