在众多的数学思想方法中,化归是核心,教材中多处运用化归思想分析解决问题.下面以一题多解为例,谈谈化归思想的应用.【例】已知tanα=3,求sinαcosα的值.(数学第一册(下)复习参考题四4组第9题(2))一、把未知化归为已知,就是利用三角函数定义或平方关系,把求sinαcosα化归为si In many mathematics thinking methods, transformation is the core, and many teaching materials are applied to the analysis and solution of problems. The following uses multiple solutions as an example to talk about the application of returning the idea. [Example] Known tanα=3 , find the value of sin α cos α. (Mathematics Volume 1 (below) Review Reference Question 4 4 Group 9 (2)) First, the unknown is classified as known, is the use of trigonometric function definition or square relationship, the sin α cos α Classified as si