The Facts On File Algebra Handbook

and the work turns into a three-volume compilation that is

finally published in 1509.

1498 lJOHANNES WIDMANwrites Mercantile Arithmetic,in which

the symbols of + and – are introduced in a book for the first

time.

1499 lPacioli and da Vinci flee the politically volatile city of

Milan, ultimately ending up in Florence, where they become

housemates for the next seven years.

1525 lCHRISTOFF RUDOLFFinvents the symbol for SQUARE ROOT,

which is published in his algebra book, Die Coss.

1533 lDutch geographer Reiner Dokkum suggests that longitude can

be determined by using the position of the Sun and a clock.

1539 lMathematician GEORG JOACHIM VON LAUCHEN RHETICUS

visits Nicolaus Copernicus, and raises funds to publish his

Narratio Prima,which ultimately gains a reputation as the

best introduction to Copernicus’s work.

1540 lROBERT RECORDEpublishes an arithmetic book, Grounde of

Artes,which is the first to use the plus sign to signify an

excess and the minus sign to signify a deficiency.

1541 lRheticus convinces Duke Albert of Prussia to fund the

printing of Copernicus’s De Revolutionibus,and elaborates

the book with his own trigonometry tables. These are the

first published tables to include cosines, and Rheticus’s

contribution to mathematics is considered to be of

astronomical value.

1545 lFerrari’s solution of the QUARTIC EQUATIONis published in

Girolamo Cardan’s book, The Great Art, or the Rules of

Algebra,but since the world is three-dimensional and

Ferrari’s work dealt with taking a quantity to the fourth

power, his work is thought to be ridiculous.

1557 lRobert Recorde introduces the EQUALS SIGN, =, in his book

Whetstone of Witte,based on his belief that nothing is more

equal than PARALLELlines. Nonetheless, mathematicians

continue to write the word, instead of using a symbol, until

1498 – 1557 CHRONOLOGY

1498 – 1557 CHRONOLOGY