当X等于多少时,(tan^2x-tanx+1)/(tan^2x+tanx+1)有最大值?

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/27 17:48:35
当X等于多少时,(tan^2x-tanx+1)/(tan^2x+tanx+1)有最大值?当X等于多少时,(tan^2x-tanx+1)/(tan^2x+tanx+1)有最大值?当X等于多少时,(tan

当X等于多少时,(tan^2x-tanx+1)/(tan^2x+tanx+1)有最大值?
当X等于多少时,(tan^2x-tanx+1)/(tan^2x+tanx+1)有最大值?

当X等于多少时,(tan^2x-tanx+1)/(tan^2x+tanx+1)有最大值?
令a=tanx,a属于R
y=(a^2-a+1)/(a^2+a+1)
ya^2+ya+y=a^2-a+1
(y-1)a^2+(y+1)a+(y-1)=0
判别式大于等于0
(y+1)^2-4(y-1)^2>=0
(y+1+2y-2)(y+1-2y+2)>=0
(3y-1)(-y+3)>=0
(3y-1)(y-3)