1)sin(-1920°)=-sin(1920°)=-sin(5×360°+120°)=-sin120°=-sin(90°+30°)=-cos30°=-√3/22)cos(-1560°)=cos(1560°)=cos(4×360°+120°)=cos(120°)=cos(90°+30°)=-sin30°=-1/23)tan(-17∏/60)=-tan(17...