一般说来,与三角函数有关的综合题主要出现在一元二次方程中,由于它综合了三角、方程、几何等方面的知识,因此,解答这类问题常常要用到以下三方面的知识: 1.同一个解的三角函数的关系式,即sin2α+cos2α=1,tgα·ctgα=1,tgα=sinα/cosα,ctgα=cosα/sinα; In general, the comprehensive questions related to trigonometric functions mainly appear in the one-dimensional quadratic equation. Because it synthesizes the knowledge of triangles, equations, and geometry, the following three kinds of knowledge are often used to solve such problems: 1. The relationship of the trigonometric function of the same solution, ie, sin2α+cos2α=1, tgα·ctgα=1, tgα=sinα/cosα, ctgα=cosα/sinα;