|Died||9 June 1751 (aged 70–71)
|Fields||Mathematician and astronomer|
|Notable students||Brook Taylor|
|Known for||Machin-like formula|
John Machin (bapt. c. 1686 – June 9, 1751), a professor of astronomy at Gresham College, London, is best known for developing a quickly converging series for Pi in 1706 and using it to compute Pi to 100 decimal places.
Machin's formula is:
The benefit of the new formula, a variation on the Gregory/Leibniz series (Pi/4 = arctan 1), was that it had a significantly increased rate of convergence, which made it a much more practical method of calculation.
To compute Pi to 100 decimal places, he combined his formula with the Taylor series expansion for the inverse tangent. (Brook Taylor was Machin's contemporary in Cambridge University.) Machin's formula remained the primary tool of Pi-hunters for centuries (well into the computer era).
Several other Machin-like formulae are known.
|Part of a series of articles on the|
|mathematical constant π|
- Anita McConnell, ‘Machin, John (bap. 1686?, died 1751)’, Oxford Dictionary of National Biography, Oxford University Press, 2004. Accessed 26 June 2007. doi:10.1093/ref:odnb/17533
- Machin's Formula at MathWorld
- List of Subscribers to the Cyclopaedia at library.wisc.edu