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Mathematicians Of The Day
5th May
On this day in 1777, Leonhard Euler was the first to use the symbol i for in the paper De Formulis Differentialibus Angularibus maxime irrationalibus quas tamen per logarithmos et arcus circulares integrare licet [Of the most irrational Angular Differential Formulas, which, however, may be integrated by means of logarithms and circular arcs], presented to the St Petersburg Academy:-
See THIS LINK.
Quoniam mihi quidem alia adhuc via non patet istud praestandi nisi per imaginaria procedendo, formulam littera i in posterum designabo, ita ut sit i i = -1 ideoque 1/i = -i.[Since there is still no other way clear to me of accomplishing this except by an imaginary procedure, I will denote the formula by the letter i in the future, so that i i = -1 and therefore 1/i = -i.]
See THIS LINK.
Click on Ⓟ for a poster.
Born:
- 1580: Johann Faulhaber Ⓟ
- 1833: Lazarus Fuchs Ⓟ
- 1860: Charles Chree Ⓟ
- 1877: Alexander Brown
- 1883: Anna Johnson Wheeler Ⓟ
- 1889: René Eugène Gateaux Ⓟ
- 1895: Stefan Bergman Ⓟ
- 1897: Francesco Tricomi Ⓟ
- 1904: Alston Householder Ⓟ
- 1905: Margaret E Boyle Ⓟ
- 1923: Cathleen Morawetz Ⓟ
Died:
- 1859: Lejeune Dirichlet Ⓟ
- 1901: Georg Zehfuss Ⓟ
- 1954: Ethel Elderton
- 1957: Leopold Löwenheim Ⓟ
- 1972: William Whyburn Ⓟ
- 1989: Stefan Warschawski Ⓟ
- 2002: Barry Johnson Ⓟ
- 2020: Sergei Ivanovich Adian Ⓟ
Quotation of the day
From Stefan Bergman
I like your result. Let's make it a joint paper and I'll write the next one.
