∴-b/2a=-2
∴b=4a
The maximum value of y is 1.
∴(4ac-b？ )/4a= 1
∫A(- 1, 0) brings y=ax? +bx+c
∴a-b+c=0
∫b = 4a gives a-b+c=0.
∴c=3a,b=4a
Bring c=3a and b=4a into (4ac-b? )/4a= 1
A=- 1 means b=-4 and c=-3.
∴ The analytical formula is y=-x? -4x-3