Let R denote a non-negative rational number. Determine a fixed set of integers a,b,c,d,e,f, such that for every choice of R, \left| \frac{aR^2\plus{}bR\plus{}c}{dR^2\plus{}eR\plus{}f}\minus{}\sqrt[3]{2}\right| < \left|R\minus{}\sqrt[3]{2}\right|. geometry3D geometryinequalities