Graphing calculators

A graphing calculator (also graphics / graphic calculator) is a handheld calculator that is capable of plotting graphs, solving simultaneous equations, and performing other tasks with variables. Most popular graphing calculators are also programmable, allowing the user to create customized programs, typically for scientific/engineering and education applications. Because they have large displays, graphing calculators also typically display several lines of text and calculations at the same time.

Casio produced the first commercially available graphing calculator, the fx-7000G, in 1985. Casio's innovations include an icon menu for easy access to functions (1994, FX-7700GE and later), graphing in several colors (1995, CFX-9800G), textbook-like "Natural Display" input and output (2004, FX-82ES/300ES & FX-9860G), expandable memory (2005, FX-9860SD), backlit screen (2006, FX-9860G Slim), full-color, high resolution backlit screen (2010, FX-CG10/CG20 PRIZM).

Sharp produced its first graphing calculator, the EL-5200, in 1986. Since then Sharp's innovations include models with a touchscreen (EL9600 series), Equation Editor (textbook-like input) (EL-9300? ( 199? ) and later), and reversible keyboard to ease learning (one side has basic functions, the other side has additional functions) (March 2005, EL-9900).

Hewlett Packard followed in the form of the HP-28C. This was followed by the HP-28S (1988), HP-48SX (1990), HP-48S (1991), and many other models. Models like the HP 50g (2006) or the HP Prime (2013) feature a computer algebra system (CAS) capable of manipulating symbolic expressions and analytic solving. An unusual and powerful CAS "calculator" is the now obsolete year 2001 Casio Cassiopeia A-10 and A-11 (flip top) stylus-operated PDAs, which ran the Maple V symbolic engine. The HP-28 and -48 ranges were primarily meant for the professional science/engineering markets; the HP-38/39/40 were sold in the high school/college educational market; while the HP-49 series cater to both educational and professional customers of all levels. The HP series of graphing calculators is best known for its Reverse Polish notation (RPN) / Reverse Polish Lisp (RPL) interface, although the HP-49G introduced a standard expression entry interface as well.

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