Posted in pi, trigonometry.

A lovely curiosity came my way via @mikeandallie and @divbyzero: In 1992 Daniel Shanks observed that if p~pi to n digits, then p+sin(p)~pi to 3n digits. For instance, 3.14+sin(3.14)=3.1415926529… — Dave Richeson (@divbyzero) July 15, 2016 Isn't that neat? If I use an estimate $p = 3.142$, then this method

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Posted in circles, geometry, pi, trigonometry.

There was a post here, but it's not here any more! Instead, it's over at the Aperiodical, as part of their $\pi$ Day approximation challenge.

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Posted in in praise of..., pi.

Happy Pi Day! mu-tant cow pi by janemariejett In the American date format, today is 3.14 - a pretty good approximation to $\pi$, which (as any fule kno) is the ratio between a circle's diameter and circumference. It's also the focus of most of the jokes about maths, because -

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