Respuesta :

[tex]if\ x_1\ and\ x_2\ zeros,\ then\ quadratic\ function\:\\\\f(x)=a(x-x_1)(x-x_2)\\\\\\9;\ -4-zeros,\ then:\\\\f(x)=a(x-9)(x+4)=a(x^2+4x-9x-36)=a(x^2-5x-36)\\\\\\if\ a=1\ then\ f(x)=x^2-5x-36[/tex]