How to judge whether a, B and C are positive or negative or equal to 0 according to the image of quadratic function What's more, for example, how can you judge 4A + 3B + C according to the image

How to judge whether a, B and C are positive or negative or equal to 0 according to the image of quadratic function What's more, for example, how can you judge 4A + 3B + C according to the image

Opening upward a > 0, opening downward A0,
The axis of symmetry is on the left side of the y-axis-b / 2A