A:
B:
已知曲线C1的参数方程是x=2cosθy=2+2sinθ(θ为参数),以坐标原点为极点,x轴的正半轴为极轴,建立极坐标系,曲线C2的极坐标方程是ρ=﹣4cosθ.
(1)求曲线C1与C2交点的极坐标;
(2)A、B两点分别在曲线C1与C2上,当|AB|最大时,求△OAB的面积(O为坐标原点).
化学反应前后肯定发生变化的是( )
先帝创业未半而中道崩殂。
He won in the story competition and his parents were very .