# Non-trivial values of error function erf(x)\operatorname{erf}(x)?

The so called error function $\operatorname{erf}(x)$ is defined as

and it is well known that $\operatorname{erf}(\infty)=1$.

Are there any other known closed-form values of $\operatorname{erf}(x)$, except for $\operatorname{erf}(0)$ and $\operatorname{erf}(\pm\infty)$?

If the values aren’t listed on the Wolfram function page, I would be surprised if you found them anywhere else. The only listed closed form values are for $$00$$, $$±∞\pm\infty$$, and $$±i∞\pm i\infty$$. However, you can find various equivalent formulations, continued fractions, and the like on that page. A good reference, generally, for most well-known functions.