[1] Jahnke studied mathematics and physics at the University of Berlin, where he graduated in 1886.

In 1889 he received his doctorate from Martin-Luther-Universität Halle-Wittenberg under Albert Wangerin on the integration of first-order ordinary differential equations.

[3] In 1900 Jahnke read a paper at the International Congress of Mathematicians in Paris.

He wrote an early book on vector calculus but is now known primarily for his function tables, which first appeared in 1909.

Fritz Emde [de] (Professor of Electrical Engineering at the University of Stuttgart) contributed to later editions, as did others.