众所周知，以原点为圆心，１为半径的圆称为单位圆，其方程是ｘ２＋ｙ２＝１．在三角函数问题中，如果仔细分析题目的结构特征，充分挖掘隐含条件，寻找条件和结论与单位圆的关系进行合理构造，可得许多巧解妙证．本文拟就用单位圆求解若干三角函数问题做以下探讨求值注意... As we all know, with the origin as the center, a circle with a radius of 1 is called a unit circle, and its equation is x2+y2=1. In trigonometric function problems, if we carefully analyze the structural features of the topic, fully explore the implicit conditions, and find the conditions and the relationship between the conclusions and the unit circle, we can obtain many wonderful solutions. This paper proposes to use the unit circle to solve several trigonometric functions.