The relationship between quadratic function coefficients a, B, C and graphs

The relationship between quadratic function coefficients a, B, C and graphs

F (x) = ax ^ 2 + BX + C (1) when opening direction a > 0, opening upward a < 0, opening upward (2) when extreme value x = - B / (2a), there is extreme value, the extreme value size = (4ac-b ^ 2) / (4a) (3) intersection with X axis, when B ^ 2-4ac > 0, there are two intersections with X axis, when B ^ 2-4ac = 0, there are two intersections with X axis