已知在平面直角坐标系中,角的始边与x轴非负半轴重合。若 且,则角的终边在第_____象限。
化简=________.
sin21°+sin22°+sin23°+…+sin288°+sin289°+sin290°的值为________.
.化简: (1)=________; (2)sin2(-α)-tan(360°-α)tan(-α)-sin(180°-α)cos(360°-α)tan(180°+α)=________; (3)=________.
sin,cos,tan,从小到大的顺序是________.
若|sin(4π-α)|=sin(π+α),则角α的取值范围是________.