Duke Jing of Qi Duke Jing of Qi Duke Jing of Qi (; died 490 BC) was ruler of the State of Qi from 547 to 490 BC. Qi was a major power during the Spring and Autumn period of ancient China. His personal name was Lü Chujiu (呂杵臼), ancestral name Jiang (姜), and Duke Jing was his posthumous title. After the years of unrest as two powerful ministers, Cui Zhu and Qing Feng, sought to control the state of Qi, Duke Jing appointed Yan Ying as his prime minister, and Qi entered a period of relative peace and prosperity. Duke Jing was born
What Is Mathematics? Expectations" by Charles Dickens. According to Constance Reid, Courant finalized the title after a conversation with Thomas Mann. What Is Mathematics? What Is Mathematics? is a mathematics book written by Richard Courant and Herbert Robbins, published in England by Oxford University Press. It is an introduction to mathematics, intended both for the mathematics student and for the general public. First published in 1941, it discusses number theory, geometry, topology and calculus. A second edition was published in 1996 with an additional chapter on recent progress in mathematics, written by Ian Stewart. The book was based on Courant's course material. Although