The quadratic function f is negative only on the open interval (−2, 1/4 ) and its graph passes through the point (−1, −5). Find a,b, and c.

Answer 1

you know that the roots are -2 and 1/4.

So, y=a(x+2)(x - 1/2)

Now just use the point given to find a, and then expand if you want the coefficients.