在斜坐标系xOy中,∠xOy, . e 1 , . e 2 分别是Jc轴,轴方向的单位向量.对于坐标平面内的点P,如果 . OP =x . e 1 +y . e 2 ,则Ge,叫做P的斜坐标. (1)已知P的斜坐标为( 2 ,1)则 | . OP | =______. (2)在此坐标平面內,以O为,半径为1的_的方程是______.
【简答题】阅读理解 Different countries and different people have different manners. We must find out their customs so that they will not think us ill-mannered(没有礼貌的). Here are examples of the things that a person w...