在研究三角问题时,常会遇到有如下特点的三角不等式证明问题:不等号的一边为常数,当三角形是正三角形取等号.这类不等式的证明往往有一定技巧,且涉及不同三角函数时不等式其证明的方法亦有显著差异,让人觉得无 When studying the trigonometric problem, we often encounter the problem of the triangular inequality that has the following characteristics: one side of the inequality sign is a constant, and when the triangle is a regular triangle, the equal sign is used. The proof of this kind of inequality is often tricky and it involves different trigonometric inequalities. There is also a significant difference in the method of proof.