Graphing calculator - Wikipedia
https://en.wikipedia.org/wiki/Graphing_calculatorAn early "graphical calculator" was designed in 1921 and patented in 1925 by electrical engineer Edith Clarke. The calculator was used to solve problems with electrical power line transmission. Casio produced the first commercially available graphing calculator, the fx-7000G, in 1985. Casio's innovations include an icon menu for easy access to …