Given that the image of quadratic function y = AX2 + BX (a is not equal to 0) of X passes through a (- 1,3), then AB has the maximum value of

Given that the image of quadratic function y = AX2 + BX (a is not equal to 0) of X passes through a (- 1,3), then AB has the maximum value of

The image of y = ax ^ 2 + BX (a is not equal to 0) passes through a (- 1,3)
3=a-b
b=a-3
AB = a (A-3) = a ^ 2-3a as quadratic function
There is a minimum when a = 3 / 2
AB min - 9 / 4