Y=ax2+bx+a2+b is: y=ax2+a2,
∵ open, ∴ a > 0,
∵ intersects the Y axis on the negative semi-axis, that is, -3 < A2.
∴ does not meet the meaning of the problem;
As can be seen from Figure ②, b=0,
Y=ax2+bx+a2+b is: y=ax2+a2,
∵ opening down, ∴ a < 0,
∫ and the y axis intersects with the positive half axis, that is, 2 < A2 < 3,
∴-root No.3 < a
As can be seen from Figure ③:
∵ opening down, ∴ a < 0,
∵ Symmetry axis is on the right side of Y axis, ∴a and B have different symbols, that is, B > 0.
∫ The image intersects the positive semi-axis of the Y axis, ∴ A2+B > 0,
When x=- 1, y=0, a-b+a2+b = 0, a+a2=0,
∴a=- 1.
According to fig. 4, the opening is upward, ∴ A > 0,
∵ Symmetry axis is on the left side of Y axis, ∴a and B have the same sign, that is, B > 0.
The image intersects the Y axis on the negative semi-axis ∴a2+b=0,
Without such a and b,
∴ does not meet this question.
So choose a.
Very speechless, ..........................................! ! ! ! ! ! ! ! ! ! ! ! ! ! ! ! !