國立清華大學 數學系

Abstract：
The isoperimetric problem is probably the oldest known problem in the calculus of variation, though it is its connection with the history of Dido of Phoenicia makes it one of the favorites of researchers in the area.  According to one tecord, Dido’s brother killed her Uncle, who was also her husband, and she was forced to flee.  She took refuge in North Africa, where she was given as much land as she could keep with the hyde of an Ox.  She cleverly had the Ox-Hyde cut into strips and had her army use it to enclose a semi-circle that contained a hill, thus founding the modern city of Carthage.  A semi-circle is the maximum area for a given perimeter, a fact which was not proved until the 20th century, and has given rise to much interesting mathematics on this problem.  In this talk I will continue the story and tell you about some interesting mathematics going on in relation to this problem.