Given that the image of quadratic function passes through the point (- 1,0) (5,0), the maximum value of the function is 6, find the analytic expression of the function

Given that the image of quadratic function passes through the point (- 1,0) (5,0), the maximum value of the function is 6, find the analytic expression of the function

According to the meaning of the problem, the quadratic function must open downward and get the maximum value at the vertex
Let y = f (x) = a (x + 1) (X-5) (a)