给出下列命题:①椭圆的离心率,长轴长为;②抛物线的准线方程为③双曲线的渐近线方程为;④方程的两根可分别作为椭圆和双曲线的离心率.其中所有正确命题的序号是
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________.