If the parabola y = ax ^ 2 + BX + C is symmetric about the Y axis, then B =? How to distinguish the symmetry axis of quadratic function from X axis or Y axis?

If the parabola y = ax ^ 2 + BX + C is symmetric about the Y axis, then B =? How to distinguish the symmetry axis of quadratic function from X axis or Y axis?

The parabola y = ax ^ 2 + BX + C is symmetric about the Y axis, that is, its axis of symmetry is y = 0
Symmetry axis of parabola y = ax ^ 2 + BX + C
It is: - B / 2A
It can be seen from the above that - B / 2A = 0
Because the image of y = ax ^ 2 + BX + C is a parabola, a is not equal to 0
-B / 2A = 0, so B = 0

It is known that the square of parabola y = - x + 2 (M + 1) x + M-3 and X-axis intersect at two points AB, a is on the right side of B, and OA / ob = 3 / 1, then M =?
also. B is distributed on both sides of the origin

Let the two intersections of parabola and X axis be n and 3N respectively, and N > 0
Then: n + 3N = 2 (M + 1), 3N & sup2; = 3-m
M = (- 5 ± √ 55) / 3
n=(m+1)/2={[(-5±√ 55)/3]+1}/2
Because: n > 0
So: M = [(√ 55) - 5] / 3 holds
That is: M = [(√ 55) - 5] / 3