三角换元将代数函数化为三角函数,关键是构造元和设元,将问题移至新对象的知识背景中去研究,从而使高中数学非标准型问题标准化、复杂问题简单化,可以把分散条件联系起来,或把隐含条件显示出来,或把条件与结论联系起来,通过转化将原来陌生、抽象、复杂问题转化为熟悉、具体、简单的问题,获得简捷优美的解法。 Triangles convert algebraic functions into trigonometric functions. The key is to construct elements and design elements, and to move the problem into the knowledge of new objects to study, so that the standardization and complexity of non-standard problems in high school mathematics can be simplified. Conditions are linked, or implicit conditions are displayed, or conditions are connected with conclusions. Through transformation, the strange, abstract, and complex issues are transformed into familiar, specific, and simple problems, and simple and elegant solutions are obtained.