A rational approximation for the exponential appearing in the theory of thermally stimulated processes (Q2644879)

Let \(E(x)=\int^{\infty}_{1}(e^{-xt}/t^ 2)dt\) and \(L(x)=1-xe^ xE(x).\) The following rational approximations for \(x\geq 10\) are presented: \(\exp \{L(x)\}\approx (x+4)/(x+2);\exp \{L(x)\}\approx (x+3.740)/(x+1.752).\) An application to the first-order theory of thermally stimulated processes is given.