sin(-7/6π)=-sin(7/6π)=sin(π+1/6π)=-sin(1/6π)=1/2
sin(-1300°)=sin(140°-4*360°)=sin(140°)=sin(50°+90°)=cos(50°)=0.643
sin(-79/6π)=sin(-12π-7/6π)=sin(-7/6π)=1/2sin(-79/6π)=sin(-12π-7/6π)=sin(-7/6π)=1/2 ?是这样做么你的sin(-7/6π)是六分之七π的意思么，是的就是那样做的THANKS