【简答题】已知:抛物线y=ax 2 +bx+c(a≠0)的对称轴为x=﹣1,与x轴交于A,B两点,与y轴交于点C,其中A(﹣3,0),C(0,﹣2) (1)求这条抛物线的函数表达式; (2)已知在对称轴上存在一点P,使得△PBC的周长最小.请求出点P的坐标; (3)若点D是线段OC上的一个动点(不与点O、点C重合).过点D作DE∥PC交x轴于点E.连接PD、PE.设CD的长为m,△PDE的面积为S.求S与m...
【多选题】Why William still had a restless life after his crown?
A.
Normans were hungering the riches of the English.
B.
William did not know how to rule his country.
C.
William was troubled by his sons' endless quarrel.
D.
William couldn't know how to speak English.
【判断题】william shakespeare is a great poet and much is known of his life. ()
【简答题】已知:抛物线y=ax 2 +bx+c(a≠0)的对称轴为x=-1,与x轴交于A,B两点,与y轴交于点C,其中A(-3,0),C(0,-2) (1)求这条抛物线的函数表达式; (2)已知在对称轴上存在一点P,使得△PBC的周长最小.请求出点P的坐标; (3)若点D是线段OC上的一个动点(不与点O、点C重合).过点D作DE ∥ PC交x轴于点E.连接PD、PE.设CD的长为m,△PDE的面积为S.求S...
【单选题】下列工程造价中,由承包单位编制、发包单位或其委托的]:程造价咨询机构审查的是( )。