三角变换的常用技巧方法订六种,即化“异”为同(减元,减类,异名化同名,复角的化单角);降高为低(降幂):灵活转化(特殊他(?)特殊角的三角函数);角度的巧妙分解与组合;活用公式(逆用与变用):运用换元或坐标法将问题转化为代数问题与 Triangular transformation commonly used techniques set six kinds of methods, that is, the “extraordinary” is the same (decrease, subtract class, synonym of the same name, complex angle of the single angle); drop high to low (descend power): flexible transformation (special The trigonometric functions of his (?) special angles); the clever decomposition and combination of angles; the use of formulae (inverse and variable): transformation of problems into algebraic problems with the use of substitutions or coordinate methods