- $x^3 - 2 x - 5 = 0$
Its approximate value is:
- $2 \cdotp 09455 \, 1 \ldots$
Also known as
The name of this number is also presented as Wallis' number.
Source of Name
This entry was named for John Wallis.
It has subsequently been used as a test for a number of different methods of approximation.
It is known to over $4000$ digits.
- April 1984: Fred Gruenberger: How to handle numbers with thousands of digits, and why one might want to (Scientific American Vol. 250, no. 4: 19 – 26)