Functions+&+Graphs



Here are some links that can also help with vocabulary of Functions and Graphs:

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[]  **Constant of Variation for a Direct Variation-** The ratio between two variables in a direct variation. Let k= the constant of variation k= y/x -OR- y= kx media type="youtube" key="wKXXrBV_RcA" width="425" height="350"

Let k= the constant of the variation k= xy -OR- y= k/x media type="youtube" key="YkGBiyZgElM" width="425" height="350"
 * Constant of Variation for an Inverse Variation- ** The product of two variables, x and y.


 * Coordinate Plane- ** The plane formed by the vertical axis and horizantal axis, often labled the x-axis and y-axis

**Dependent Variable-** A variable that depends on one or more other variables. For example: in the equation y= 6x + 4, y is the dependent variable because its value depends on what the value of x is. Usually the dependent variable is the one isolated on one side of the equation.
 * Coordinates- ** On the coordinate plane, the pair of numbers giving the location of a point (ordered pair).

If you double x (from 1 to 2), y doubles (from 3 to 6). If you triple x(from 1 to 3), y triples (from 3 to 9).The relationship is directly proportional.
 * Direct Variation- ** A relationship between two variables where if one variable changes, the other changes in proportion.


 * Domain- ** The set of first numbers in an ordered pair in a relation; the x-value in an ordered pair (x,y). In the pair (2,4), 2 would be the domain.


 * Function- ** A relation where each domain corresponds to exactly to one range. Two domains can go to the same range, but one domain can not go to two different ranges.


 * Independent Variable- ** A variable in the equation who's value is freely chosen without depending on any other variable. In the equation y= 6x + 4, x is the independent variable because it does not depend on the value of y. The varlible y is not independent because its value depends on what the value of x is.

**Inverse Variation-** A relationship between two variables in which the product is a constant. When one variable increases the other decreases in proportion so that the product is changed. Doubling //x// causes //y// to halve. The product of //x// and //y// is always 60.
 * Example:**  Equation: //y// = 60///x// //y// is inversely proportional to //x//.
 * //x// || //y// ||
 * 3 || 20 ||
 * 6 || 10 ||
 * 12 || 5 ||


 * Ordered Pair- ** The two numbers giving the location of a point. The ordered pair is written in the form (x,y).

**Origin-** On a coordinate plane, the point (0,0). The point of intersection of the x- and y-axes.


 * Quadrants- ** The four sections in which the x- and y-planes are divided by the x- and y-axes -OR- The four sections on a coordinate plane.



** Range- ** The set of the second of each ordered pair in a relation; the y-value in an ordered pair (x.y). In the ordered pair (2,4), 4 would be the range.

For example: {(3,0), (5,2), (2,4)}
 * Relation- **A set of ordered pairs.


 * Vertical Line Test- ** A test used to determine if a relation is a function. A relation __is__ a function if there are no vertical lines that intersect the graph at more than one point.





**X-axis-** The horizontal axis on a coordinate plane

**Y-axis**- The vertical axis on a coordinate plane

This sums up some of the terms: