Several analytic expressions of mathematical quadratic function What general form, vertex form and so on. Be clear
The quadratic function can be expressed as f (x) = ax ^ 2 + BX + C (a is not 0). Its image is a parabola whose principal axis is parallel to y axis
In general, the relationship between independent variable x and dependent variable y is as follows:
General formula: 1: y = ax ^ 2; + BX + C (a ≠ 0, a, B, C are constants), then y is called the quadratic function of X
Number. Vertex coordinates (- B / 2a, (4ac-b ^ 2) / 4A)
2: Vertex formula: y = a (X-H) ^ 2 + K or y = a (x + m) ^ 2 + K (the two formulas are essentially the same,
But it's the first formula in junior high school textbooks.)
3: Intersection (and X-axis): y = a (x-x1) (x-x2)