Calculator for example, solve quadratic equations symbolically. The first graphing calculator was the Casio fx-7000G released in 1985. The two leading manufacturers, HP and TI, released increasingly feature-laden calculators during the 1980s and 1990s. At the turn of the millennium, the line between a graphing calculator and a handheld computer was not always clear, as some very advanced calculators such as the TI-89, the Voyage 200 and HP-49G could differentiate and integrate functions, solve differential equations, run word processing and PIM software, and connect by wire or IR to other calculators/computers. The HP 12c financial calculator is still produced. It was
Union Electric Company primarily in Missouri, where more than half of its customers reside in the St. Louis metropolitan area. It also serves adjoining parts of Illinois, and formerly served Iowa as well through the mid-1990s. Union Electric Company The Union Electric Company of Missouri (formerly ) was an electric power utility that was organized in 1902 and grew to be one of the S&P 500 largest companies in the United States. In 1997, its holding company merged with a smaller neighboring utility, Central Illinois Public Service Company through its holding company, CIPSCO Inc. (formerly ), to form Ameren Corporation () based in