Math for everyone
Mathematical content accessible to everyone

Antoine Pevsner: homage to the straight line
In 1956, the sculptor Antoine Pevsner declared: "The most important feature of my work today […], the principle on which all my sculpture is now built, is the exclusive use of straight lines."

The semantics of droite | Tangente
A good droite is not necessarily mathematical: you find it in politics just as in boxing…

The definition of the straight line through the ages
You thought you knew what a straight line is? Read on, and you may well start to doubt it…

Mathematical vs astrological semantics | Tangente
Horoscope advice can seem sensible. Why is that? While advice in objective areas consists solely of tautologies, subjective advice draws on a multiplicity of meanings, allowing clients always to interpret it as they wish.

Astrological calculations: how consistent are they?
The notion of houses, which originated with the Babylonians, who mainly observed the movements of the stars in the sky as seen from Earth, is an early form of astrology.

How to calculate cube roots by hand | Tangente
Have you mastered the square root algorithm? Impress your friends with cube root extraction!

Roots in the complex plane
The idea of a root extends readily to the field of complex numbers. In fact, it is even more at home there than among the real numbers, since this extension gives it a geometric interpretation. Welcome to the fascinating mathematical world of cyclotomy!

Sylvie Donmoyer, an artist fascinated by mathematics
An artist, not a mathematician, Sylvie Donmoyer is fascinated by geometric forms. In one engraving after another, inspired by Dürer and above all by Escher, she weaves connections between the two worlds of art and mathematics.

From Bézout's theorem for polynomials to the intersection of conics
Étienne Bézout is known for two theorems. One generalizes Bachet's theorem from integers to polynomials; the other concerns the intersection points of algebraic curves. The two are in fact related, but in a subtle way.

Bachet and Bézout: a winning mathematical duo
From Gauss's lemma to the Chinese remainder theorem, by way of numerous Diophantine equations, no problem seems able to resist the Bachet–Bézout theorem. Games, recreational puzzles, arithmetical tricks… Let's dive into mathematics!

A happy identity
The famous Bézout theorem—actually proved earlier by Bachet de Méziriac—may look simple, but it opens up many avenues in both arithmetic and algebra. This discovery makes it easier to solve a great many Diophantine equations, among other things...

The planets are not to blame: moon and birth | Tangente
Some arguments from astronomy can be set against the beliefs spread by astrology.

What is a pseudo-science? Astrology | Tangente
Despite terms borrowed from astronomy, the inconsistencies that emerge when the scientific method is applied to astrology strip it of all credibility. It is what is known as a pseudo-science.

Using probability to demystify astrology
Astrology has been fostered both by obscurantists, who believe in pseudoscientific laws that can be proven false, and by charlatans who exploit coincidences that are not really coincidences to drum up business. In both cases, probability can expose them.

Salon 2016: maths transform our society | Tangente
The unmissable Salon Culture et Jeux Mathématiques will run from Thursday 26 to Sunday 29 May on Place Saint-Sulpice. Save these dates for the (free) mathematics event of the year!

Pierre Boulez, mathematics and glory | Tangente
"Music is a hidden practice of arithmetic, the mind unaware that it is counting," said Leibniz. Pierre Boulez, who died on 5 January, conductor, composer and teacher of music and musical composition all at once, revealed to the whole world the hidden face of "his" music, in which mathematics runs through like a watermark.

Root extraction
Newton's method is a general method for finding the solution to an equation of the form f (x) = 0 by applying a simple algorithm.

Square roots
"The square root is my favorite," declared Boris Vian in Racine carrée (Square Root) in 1957. From antiquity to modern high-performance computing, many methods have been devised to calculate square roots in practice.

Mega primes: A new GIMPS record | Tangente
A quest that may seem far-fetched or pointless to some, but is of the utmost importance for our secret codes, is that of "mega primes" — in other words, prime numbers with more than a million digits.

The proportional compass
Two thin, hinged plates for calculating proportions.
