Johann Rahn
Encyclopedia
Johann Rahn (1622–1676) was a Swiss mathematician
who is credited with the first use of the division symbol, ÷ (obelus
) and the therefore sign
, ∴. The symbol is used in Teutsche Algebra, published in 1659.
Mathematician
A mathematician is a person whose primary area of study is the field of mathematics. Mathematicians are concerned with quantity, structure, space, and change....
who is credited with the first use of the division symbol, ÷ (obelus
Obelus
An obelus is a symbol consisting of a short horizontal line with a dot above and below. It is mainly used to represent the mathematical operation of division. It is therefore commonly referred to as the division sign.- History :The word "obelus" comes from the Greek word for a sharpened stick,...
) and the therefore sign
Therefore sign
In a mathematical proof, the therefore sign is a symbol that is sometimes placed before a logical consequence, such as the conclusion of a syllogism. The symbol consists of three dots placed in an upright triangle and is read therefore. It is encoded at . While it is not generally used in formal...
, ∴. The symbol is used in Teutsche Algebra, published in 1659.