Given that the increasing interval of quadratic function y = AX2 + BX + C is (- ∞, 2), then the increasing interval of quadratic function y = bx2 + ax + C is______ ．

The increasing interval of quadratic function y = AX2 + BX + C is (- ∞, 2), so a < 0, b > 0, and − B2A = 2, then − A2B = 18, the opening of quadratic function y = bx2 + ax + C is upward, the symmetry axis is x = 18, so the increasing interval of quadratic function y = bx2 + ax + C is: [18, + ∞). So the answer is: [18, + ∞)

It is known that the monotone increasing interval of quadratic function y = ax ^ 2 + BX + C is (negative infinity, 2]
Ask [0,2] is the monotone increasing interval of quadratic function y = ax ^ 2 + BX + C. is this proposition right? Why?

No, it is the monotone increasing of quadratic function y = ax ^ 2 + BX + C in [0,2]

Finding monotone interval of quadratic function y = ax ^ 2 + BX + C (A0)
I also find x = - B / 2a, but how to judge the increase or decrease interval? Do it with derivative

a> Monotone increasing interval [- B / 2a, + ∞) at 0
Monotone decreasing interval (- ∞, - B / 2A]
a