1
π5/6>=3x-π/6>=π/6
π/3>=x>=π/9
sin(π/6)=sin(π-π/6)=sin(5/6π)=1/2
2
同理
π/6>=2x-π/3>=-π/6
π/4>=x>=π/12
cos(30`)=cos(-30`)
3
2sin(-4x+π/4)
三角函数-求x的范围呃…突然不知道怎么做了 = =|| 呃…题目如图：麻烦各位写下过程~谢了啊~
1
π5/6>=3x-π/6>=π/6
π/3>=x>=π/9
sin(π/6)=sin(π-π/6)=sin(5/6π)=1/2
2
同理
π/6>=2x-π/3>=-π/6
π/4>=x>=π/12
cos(30`)=cos(-30`)
3
2sin(-4x+π/4)