负3分之17兀的正切,正弦,余弦

Question

负3分之17兀的正切,正弦,余弦

Answer 1

sin(-17π/3)=sin(-6π+π/3)=sin(π/3)=(√3)/2（sin是周期函数,sin(x+2kπ)=sin(x)）
cos(-17π/3)=cos(-6π+π/3)=cos(π/3)=1/2（cos也是周期函数,cos(x+2kπ)=cos(x)）
tan(-17π/3)=sin(-17π/3)/cos(-17π/3)=√3