Find the quadratic function that goes through the points ( 0, f(0) ), (deltax, f(deltax) ), ( 2deltax, f(2deltax) ). In other words find the values of a, b, and c such that those points satisify the equation g(x) = ax^2 + bx + c. Hint g(0) = f(0)

Alright, i'm not getting how to do this at all, can anyone lead me in the right direction?