(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

Question

(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

Answer 1

x=-b/2a,y=(4ac-b^2)/4a
(2)x-b/2a,x=-b/2a,y=(4ac-b^2)/4a