tan3分之11派=tan(4π-π/3)=-tan(π/3)=-√3；
sin3分之17派=sin(6π-π/3)=-sin(π/3)=-√3/2
cos(-6分之7派)=cos(7π/6)=cos(π+π/6)=-cos(π/6)=-√3/2
tan(-4分之7派)=tan(-2π+π/4)=tan(π/4)=1
sin900°=sin(720°+180°)=sin180°=0