Fuente TeX:

\frac{1+e^{-x} }{log(x) (1+x log^{\alpha} (x))}=\frac{1+e^{-x} }{log(x) + x log^{\alpha +1} (x)}=\frac{1 }{log(x) + x log^{\alpha +1} (x)} +\frac{e^{-x} }{log(x) + x log^{\alpha +1} (x)}