(1)因为二次函数y=ax^2+bx+c可配方成y=a(x+____)^2+____,所以其顶点坐标是_____,对称轴方程为_______,

问题描述:

(1)因为二次函数y=ax^2+bx+c可配方成y=a(x+____)^2+____,所以其顶点坐标是_____,对称轴方程为_______,
并且当x=______时,y=______.
(2)若a>0,当______时,y随x的增大而减小;当_____时,y随x的增大而增大;当_____时,y有最_____值为_______.
(3)若a

x=-b/2a,y=(4ac-b^2)/4a
(2)x-b/2a,x=-b/2a,y=(4ac-b^2)/4a呃~~~看不懂啊!@-@当x=-b/2a时,y=(4ac-b^2)/4a

(2)若a>0,当x-b/2a, y随x的增大而增大;当x