Coordinate System

and Graphing Ordered Pairs and Relations

•Points on a coordinate plane can be located by using pairs of integers. Integers are positive and negative #’s. The coordinate plane consists of the following:

1)a horizontal axis (left to right) which is called the x-axis

2)a vertical axis (up and down) which is called the y-axis

3)the origin, (0, 0), where the x- and y- axis cross or intersect

4) an infinite set of ordered pairs or points. Points are named by using capital letters and given location by using ordered pairs. The ordered pair corresponds to location on the x- and y- axis.

For example,• Point A is located at (x, y). To

graph this point you start at the origin and move to the right (if x is positive) or left (if x is negative). Then, from that location, move up (if y is positive) or down (if y is negative). Place a point on the coordinate plane and label with the capital letter, A.

• 5) four regions called quadrants.

• Quadrant I: (+x, +y)• Quadrant II: (-x, +y)• Quadrant III: (-x, -y)• Quadrant IV: (+x, -y)

•A point is located in or on: Q1, Q2, Q3, Q4, origin, x-axis, or the y-axis

(Most textbooks or handouts only ask which quadrant. You need to choose from the above 7 locations.)

Practice (If you have the Internet, check out some of these websites. We will probably look at some in class too.)• http://www.glencoe.com/sec/math/prealg/

prealg05/extra_examples/chapter2/lesson2_6.pdf• l

http://www.math.com/school/subject2/practice/S2U4L1/S2U4L1Pract.html

• http://www.shodor.org/interactivate/activities/GeneralCoordinates/

• http://www.mste.uiuc.edu/pavel/java/chameleon/advanced/index.htm

• http://www.glencoe.com/sec/math/studytools/cgi-bin/msgQuiz.php4?isbn=0-07-825200-8&chapter=2&lesson=6&&headerFile=6&state=nc

• http://hotmath.com/help/gt/genericalg1/section_2_1.html

• http://www.funbrain.com/cgi-bin/co.cgi