Maria Gaetana Agnesi

Maria Gaetana Agnesi did not marry. She died on January 9, 1799, at the age of 80, in Milan.

The geometrical curve, ’Witch of Agnesi’, has been named after Maria Gaetana Agnesi. Originally, the Latin name of the curve was ‘versoria’. However, in Italian it became ‘versiera’, which also means devil. Agnesi had talked about the curve in length in her book ‘Instituzioni analitiche ad uso della gioventù italiana’. When the work was translated into English the curve began to be known as ‘Witch of Agnesi’.

A crater on planet Venus has been named after Maria Agnesi by the International Astronomical Union's Working Group on Planetary System Nomenclature, in 1991.

Maria Gaetana Agnesi was born on May 16, 1718, in the city of Milan, then under the crown of Habsburg. Her father Pietro Agnesi was a professor of mathematics at the University of Bologna. At the same time, he made immense wealth by trading in silk.

Maria’s mother, Anna Fortuna Brivio, was a scion of famous Brivio family of Milan. Maria Gaetana was their eldest child. The famed Italian composer, Maria Teresa Agnesi Pinottini, was her younger sister.

Pietro Agnesi was an ambitious and overbearing man. He had married Anna simply to climb up the social ladder. After her death he took two more wives. In all, he had twenty one children. Maria Gaetana had to spend a lot of time looking after her siblings.

Maria Gaetana was born genius. By the age of five, she could speak Italian and French fluently. Pietro Agnesi recognized her talent and employed the best tutors to teach her at home. All of them were learned men of the Church. Maria began her education under their tutelage.

Pietro Agnesi regularly hosted gatherings where men of learning were invited. His main purpose to host such gatherings was to show off his daughter’s talents. While Maria Gaetana had to engage in intellectual discourse her sister was asked to display her musical talent.

Maria was actually a very shy and private person. Some time now, she decided to join the church. However, her father was horrified that his most talented child wanted to become a nun and begged her to reconsider her decision. Besides, she had her siblings to look after and so she agreed to stay at home.

However, from that time onwards she began to dress humbly and stopped taking part in profane amusements such as balls and theatres. Instead, she attended the church more regularly and devoted herself to the study of Mathematics.

In 1739, Maria came across ‘Traité analitique des sections coniques’ of the Marquis Guillaume de l'Hôpital and became interested in mathematics. From 1740, she began to be guided by Father Ramiro Rampinelli, who later became professor of mathematics at the University of Pavia. With him, she studied differential as well as integral calculus.

In 1748, on the advice of Rampinelli, she published ‘Instituzioni analitiche ad uso della gioventù italiana’ (‘Analytical Institutions for the Use of Italian Youth’), in two big volumes. It was a text book on mathematics and some believe it was aimed educating her younger siblings.

Maria Gaetana dedicated the books to Empress Maria Theresa of Austria, who honored her with a personal letter, a diamond ring and a case studded with diamonds and crystals.

Pietro Agnesi died in 1752 and with that Maria Agnesi became free to study her favorite subject theology. At the same time, she devoted herself to the cause of poor, homeless and sick. She spent all her money in charity and at times had to resort to begging to continue with her work.

In 1762, Agnesi was asked by the University of Turin to give her opinion on the recent articles on the calculus of variations by young Lagrange; she refused. She wrote back saying she was no more interested in such matters.

In 1783, she founded a home for old people and became its director. Here she lived as a nun, taking care of the inmates.