求三角函数最值问题中的参数值问题,是三角中的一个重要内容.而在教材或一些读物中其习题甚少,笔者就以自己积累的资料加以整理,供学习参考.一、应用三角函数值域:|sinx|≤1,|cosx|≤1.例1已知x∈[0,π4],函数f(x)=2asin2x-23asinxcosx+a+b(a0)的最大值为1,最小值为-5,求a、b The problem of finding the parameter value in the problem of the trigonometric function is an important part of the triangle. However, in the textbooks or some of the readings, there are very few exercises. The author will use his own accumulated information to organize and provide reference for learning. Function value range: |sinx|≤1,|cosx|≤1. Example 1 Known x∈[0,π4], function f(x)=2asin2x-23asinxcosx+a+b(a0) has a maximum value of 1, The minimum value is -5, find a, b