用不等号连接的含有三角函数的式子简称为三角不等式.在我国高中数学竞赛中,关于三角不等式的问题有三类,一是三角不等式的证明,二是解三角不等式,三是应用三角三不等式求最值.处理这三类问题,既要用到不等式的有关性质,又要熟练运用三角公式进行恒等变形,有时还要利用三角函数 The equations containing trigonometric functions connected by inequalities are abbreviated as triangular inequalities. In the mathematics competition in high schools in China, there are three types of problems concerning trigonometric inequalities. One is the proof of triangular inequalities, the other is the solution of triangular inequalities, and the third is the application of triangular trinomial inequalities. The maximum value. To deal with these three types of problems, we must use the relevant properties of inequalities, but also proficient in the use of trigonometric formulae for the isomorphic deformation, and sometimes also use the trigonometric function.