Exponential Integral Functions

This calculator finds the numerical value of two exponential integral functions: \[ E_n(x) = \int_1^\infty \frac{\mathrm{e}^{-xt}}{t^n}\;dt \] and \[ E_i(x) = -E_1(-x) = -\int_{-x}^\infty \frac{\mathrm{e}^{-t}}{t}\;dt \] where $n=0,1,2,\ldots$ and $x>0$.

Exponential Integral Calculator