When the vertex of the image of quadratic function f (x) is known, m (- 2 / 3,49), the difference between the two equations f (x) = 0 is equal to 7, and the analytic expression of quadratic function f (x) is obtained

When the vertex of the image of quadratic function f (x) is known, m (- 2 / 3,49), the difference between the two equations f (x) = 0 is equal to 7, and the analytic expression of quadratic function f (x) is obtained

The equation y = a (x + 2 / 3) 2 + 49 is set by the fixed-point formula. Obviously, a is less than 0. Because the difference between the two equations is equal to 7, then the square of the difference between the two equations is equal to 49. The sum of the two equations and the product of the two equations can be used to express a = - 4