English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We have shown recently that integration of the error function${\rm{erf}}\left( x \right)$ represented in form of a sum of the Gaussianfunctions provides an asymptotic expansion series for the constant pi. In thiswork we derive a rational approximation of the arctangent function $\arctan\left( x \right)$ that can be readily generalized it to its counterpart $ -{\rm{sgn}}\left( x \right)\pi /2 + \arctan \left( x \right)$, where${\rm{sgn}}\left( x \right)$ is the signum function. The application of theexpansion series for these two functions leads to a new asymptotic formula for$\pi$.

A rational approximation of the arctangent function and a new approach in computing pi