-4/3 + ep*(-4/3 + 4/(3*x) + (2*x)/3) + ep^2*(-4/3 + 4/(3*x) + (2*x)/3) + 
 ep^3*(-4/3 + 4/(3*x) + (2*x)/3) + 4/(3*x) + (2*x)/3
