Life is _________ of unexpected things. Some bring us happiness, but some bring us sadness. A. have B. filled C. full D. made 答案:C已知:二次函数y=x2+bx+3的图象经过点(3,0).(1)求b的值;(2)求出该二次函数图象的顶点坐标和对称轴;(3)在所给坐标系中画出二次函数y=x2+bx+3的图象.
(1)b=-4;(2)顶点坐标是(2,-1),对称轴为直线x=2;(3)画图见解析.
【解析】试题分析:(1)将点(3,0)代入y=x2+bx+3即可得出答案;
(2)用配方法把二次函数化为顶点式,即可得到顶点坐标和对称轴;
(3)再求得抛物线与x,y轴的交点坐标即可得出较准确的图象.
试题解析:(1)将(3,0)代入函数解析式,得9+3b+3=0.解得b=-4.
(...