Maria Gaetana Agnesi (1719-1799). Born in Milan, she was a gifted scholar. She was a scientist, mathematician and later in her life she devoted herself to religious beliefs. She is most famous for the Witch of Agnesi.
Her father married 3 times and had 21 children, which she was the oldest child. Her first essay was published in Latin when she was only 9 years old. She wrote in defense of higher education for woman. By age 13 she learned and spoke more than 6 languages. In 1948 she wrote a book called "Instituzioni Analitiche" (the first surviving mathematical work written by a woman. In this book the plane curve is studied and was named the versiera, or turning curve. The versiera is now known as the "Witch of Agnesi" because a British mathematician, John Colson, translated the word versiera incorrectly. Early on this was read by Cambridge professor John Colson as "l'avversiera di Agnesi", where "avversiera" means "woman contrary to God" the word "witch" was mistranslated into English and was kept as the translation. At age 30, with the consent of the Pope, she was made an honorary staff member of the University of Bologna
This curve was studied previously by Guido Grandi in 1701 and was given the name “Verarsia”, which means "turning in every direction." Below is an example of the Witch of Agnesi as found on the page written by by Daphne Golden and Melissa Hanzsek-Brill -Department of Mathematics Education
The algebraic equation that generates this curve is
.
By substituting the values 1, 2, and 3 in for a, we get the following graphs using Algebra Xpresser.
GRAPH ONE: for a = 1, 2, and 3 In order to "turn" the curve onto the x-axis, we take the inverse of the equation and obtain the equation
By substituting the same values for a, and again using Algebra Xpresser, we can obtain the following graph.
GRAPH TWO: for a = 1, 2, 3.
Wikipedia - http://en.wikipedia.org/wiki/Witch_of_Agnesi
New Advent- The Catholic Encyclopedia -