In this paper, two new trigonometrical inequalities are given, and applied to discuss triangle shapes.

给出两个新的三角不等式，并将其应用于讨论角成等比的三角形形状。

Trigonometrical function in the teaching of mathematics in secondary schools, have a decisive position.

三角函数的教学在中学数学教学中有着举足轻重的地位。

In this paper, the deflection and stress function in terms of trigonometrical function and polynomial expression are first proposed.

本文首先选择由三角函数和多项式组成的挠度函数和应力函数。

Trigonometrical function reflects Yuan Movement and the Movement of mutual conversion and the corresponding linear relationship is the only primary function of the cycle function .

三角函数反映了圆运动和直线运动的相互转化与对应关系，是初等函数中唯一的周期函数。