# Chronology

### 1500 - 1600

#### 1514

- Vander Hoecke uses the + and - signs.

#### 1515

- Del Ferro discovers a formula to solve cubic equations. (See this History Topic.)

#### 1522

- Tunstall publishes
*De arte supputandi libri quattuor*(*On the Art of Computation*), an arithmetic book based on Pacioli's*Summa*.

#### 1525

- Rudolff introduces a symbol resembling √ for square roots in his
*Die Coss*the first German algebra book. He understands that $x^{0} = 1$. - Dürer publishes
*Unterweisung der Messung mit dem Zirkel und Richtscheit*, the first mathematics book published in German. It is a work on geometric constructions.

#### 1533

- Frisius publishes a method for accurate surveying using trigonometry. He is the first to propose the triangulation method.

#### 1535

- Tartaglia solves the cubic equation independently of del Ferro. (See this History Topic.)

#### 1536

- Hudalrichus Regius finds the fifth perfect number. The number 212 (213 - 1) = 33550336 is the first perfect number to be discovered since ancient times. (See this History Topic.)

#### 1540

- Ferrari discovers a formula to solve quartic equations. (See this History Topic.)

#### 1541

- Rheticus publishes his trigonometric tables and the trigonometrical parts of Copernicus's work.

#### 1543

- Copernicus publishes
*De revolutionibus orbium coelestium*(*On the revolutions of the heavenly spheres*). It gives a full account of the Copernican theory, namely that the Sun (not the Earth) is at rest in the centre of the Universe.

#### 1544

- Stifel publishes
*Arithmetica integra*which contains binomial coefficients and the notation +, -, √.

#### 1545

- Cardan publishes
*Ars Magna*giving the formula that will solve any cubic equation based on Tartaglia's work and the formula for quartics discovered by Ferrari. (See this History Topic.)

#### 1550

- Ries publishes his famous arithmetic book
*Rechenung nach der lenge, auff den Linihen vnd Feder*. It taught arithmetic both by the old abacus method and the new Indian method.

#### 1551

- Recorde translates and abridges the ancient Greek mathematician Euclid's
*Elements*as*The Pathewaie to Knowledge*.

#### 1555

- J Scheybl gives the sixth perfect number 216 (217 - 1) = 8589869056 but his work remains unknown until 1977. (See this History Topic.)

#### 1557

- Recorde publishes
*The Whetstone of Witte*which introduces = (the equals sign) into mathematics. He uses the symbol "bicause noe 2 thynges can be moare equalle".

#### 1563

- Cardan writes his book
*Liber de Ludo Aleae*on games of chance but it would not be published until 1663.

#### 1571

- Viète begins publishing the
*Canon Mathematicus*which he intends as a mathematical introduction to his astronomy treatise. It covers trigonometry, containing trigonometric tables and the theory behind their construction.

#### 1572

- Bombelli publishes the first three parts of his
*Algebra*. He is the first to gives the rules for calculating with complex numbers.

#### 1575

- Maurolico publishes
*Arithmeticorum libri duo*which contains examples of inductive proofs.

#### 1585

- Stevin publishes
*De Thiende*in which he presents an elementary and thorough account of decimal fractions.

#### 1586

- Stevin publishes
*De Beghinselen der Weeghconst*containing the theorem of the triangle of forces.

#### 1590

- Cataldi uses continued fractions in finding square roots.

#### 1591

- Viète writes
*In artem analyticam isagoge*(*Introduction to the analytical art*), using letters as symbols for quantities, both known and unknown. He uses vowels for the unknowns and consonants for known quantities. Descartes, later, introduces the use of letters $x, y ...$ at the end of the alphabet for unknowns.

#### 1593

- Van Roomen calculates π to 16 decimal places. (See this History Topic.)