Changes

[[File:lighterstill.jpg]][[File:Graph_tangent.jpg|right|frame]]

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*[http://en.wikipedia.org/wiki/19th_century 1886]

*[https://en.wikipedia.org/wiki/19th_century 1886]

==Definitions==

==Definitions==

*1: the collection of all [[points]] whose coordinates satisfy a given relation (as a function)

*1: the collection of all [[points]] whose coordinates satisfy a given relation (as a function)

*2: a diagram (as a series of one or more points, lines, line segments, curves, or areas) that [[represents]] the variation of a [[variable]] in comparison with that of one or more other variables

*2: a diagram (as a series of one or more points, lines, line segments, curves, or areas) that [[represents]] the variation of a [[variable]] in comparison with that of one or more other variables

*3: a collection of [http://en.wikipedia.org/wiki/Vertices vertices] and edges that join pairs of vertices  

*3: a collection of [https://en.wikipedia.org/wiki/Vertices vertices] and edges that join pairs of vertices  

==Description==

==Description==

A '''graph''' is pictorial [[representation]] of [[statistical]] [[data]] or of a functional [[relationship]] between [[variables]]. Graphs have the [[advantage]] of showing general tendencies in the [[quantitative]] behavior of data, and therefore serve a [[predictive]] function. As mere approximations, however, they can be inaccurate and sometimes misleading.

A '''graph''' is pictorial [[representation]] of [[statistical]] [[data]] or of a functional [[relationship]] between [[variables]]. Graphs have the [[advantage]] of showing general tendencies in the [[quantitative]] behavior of data, and therefore serve a [[predictive]] function. As mere approximations, however, they can be inaccurate and sometimes misleading.

If the independent variable is not expressly [[temporal]], a bar graph may be used to show discrete [[numerical]] quantities in relation to each other. To [[illustrate]] the relative [[populations]] of various nations, for example, a series of [[parallel]] columns, or bars, may be used. The length of each bar would be [[proportional]] to the size of the population of the respective country it represents. Thus, a demographer could see at a glance that China’s population is about 30 percent larger than its closest rival, India.

If the independent variable is not expressly [[temporal]], a bar graph may be used to show discrete [[numerical]] quantities in relation to each other. To [[illustrate]] the relative [[populations]] of various nations, for example, a series of [[parallel]] columns, or bars, may be used. The length of each bar would be [[proportional]] to the size of the population of the respective country it represents. Thus, a demographer could see at a glance that China’s population is about 30 percent larger than its closest rival, India.

This same [[information]] may be [[expressed]] in a part-to-whole [[relationship]] by using a circular graph, in which a [[circle]] is divided into sections, and where the size, or angle, of each sector is directly proportional to the percentage of the whole it represents. Such a graph would show the same [[relative]] population sizes as the bar graph, but it would also [[illustrate]] that approximately one-fourth of the world’s population resides in China. This type of graph, also known as a [http://en.wikipedia.org/wiki/Pie_chart pie chart], is most commonly used to show the breakdown of items in a [[budget]].

This same [[information]] may be [[expressed]] in a part-to-whole [[relationship]] by using a circular graph, in which a [[circle]] is divided into sections, and where the size, or angle, of each sector is directly proportional to the percentage of the whole it represents. Such a graph would show the same [[relative]] population sizes as the bar graph, but it would also [[illustrate]] that approximately one-fourth of the world’s population resides in China. This type of graph, also known as a [https://en.wikipedia.org/wiki/Pie_chart pie chart], is most commonly used to show the breakdown of items in a [[budget]].

In [http://en.wikipedia.org/wiki/Analytic_geometry analytic geometry], graphs are used to map out functions of two [[variables]] on a [http://en.wikipedia.org/wiki/Cartesian_coordinates Cartesian coordinate system], which is composed of a [[horizontal]] x-axis, or abscissa, and a [[vertical]] y-axis, or ordinate. Each axis is a real number line, and their [[intersection]] at the zero point of each is called the [[origin]]. A graph in this sense is the locus of all points (x,y) that satisfy a particular function.

In [https://en.wikipedia.org/wiki/Analytic_geometry analytic geometry], graphs are used to map out functions of two [[variables]] on a [https://en.wikipedia.org/wiki/Cartesian_coordinates Cartesian coordinate system], which is composed of a [[horizontal]] x-axis, or abscissa, and a [[vertical]] y-axis, or ordinate. Each axis is a real number line, and their [[intersection]] at the zero point of each is called the [[origin]]. A graph in this sense is the locus of all points (x,y) that satisfy a particular function.

[[Category: Mathematics]]

[[Category: Mathematics]]