Texas Instruments TI-82 User Manual - Page 10

Glossary This glossary provides definitions for important terms that are used throughout this guidebook. Expression Function Graph Database Graph Picture Home Screen Instruction List Matrix Menu Items Pixel Variable An expression is a complete sequence of numbers, variables, functions, and their arguments that can be evaluated to a single answer. A function, which may have arguments, returns a value and can be used in an expression. A function is also the expression entered in the Y= editor used in graphing and TABLE. A graph database is composed of the elements that define a graph: functions in the Y= list, MODE settings, and WINDOW settings. They may be saved as a unit in a graph database to recreate the graph later. A picture is a saved image of a graph display, excluding cursor coordinates, axis labels, tick marks, and prompts. It may be superimposed on another graph. The Home Screen is the primary screen of the TI.82, where expressions can be entered and evaluated and instructions can be entered and executed. An instruction, which may have arguments, initiates an action. Instructions are not valid in expressions. A list is a set of values that the TI.82 can use for activities such as graphing a family of curves, evaluating a function at multiple values, and entering statistical data. A matrix is a two-dimensional array on which the TI.82 can perform operations. Menu items are shown on full-screen menus. A pixel (picture element) is a square dot on the TI.82 display. The TI.82 display is 96 pixels wide and 64 pixels high. A variable is the name given to a location in memory in which a value, an expression, a list, a matrix, or another named item is stored. x Introduction