Identifying Points on the Rectangular Coordinate System
Learning Outcomes
- Name the ordered pair of a point on a coordinate system
In algebra, being able to identify the coordinates of a point shown on a graph is just as important as being able to plot points. To identify the x-coordinate of a point on a graph, read the number on the x-axis directly above or below the point. To identify the y-coordinate of a point, read the number on the y-axis directly to the left or right of the point. Remember, to write the ordered pair using the correct order [latex]\left(x,y\right)[/latex].
example
Name the ordered pair of each point shown:
Solution
Point A is above [latex]-3[/latex] on the [latex]x\text{-axis}[/latex], so the [latex]x\text{-coordinate}[/latex] of the point is [latex]-3[/latex]. The point is to the left of [latex]3[/latex] on the [latex]y\text{-axis}[/latex], so the [latex]y\text{-coordinate}[/latex] of the point is [latex]3[/latex]. The coordinates of the point are [latex]\left(-3,3\right)[/latex].
Point B is below [latex]-1[/latex] on the [latex]x\text{-axis}[/latex], so the [latex]x\text{-coordinate}[/latex] of the point is [latex]-1[/latex]. The point is to the left of [latex]-3[/latex] on the [latex]y\text{-axis}[/latex], so the [latex]y\text{-coordinate}[/latex] of the point is [latex]-3[/latex]. The coordinates of the point are [latex]\left(-1,-3\right)[/latex].
Point C is above [latex]2[/latex] on the [latex]x\text{-axis}[/latex], so the [latex]x\text{-coordinate}[/latex] of the point is [latex]2[/latex]. The point is to the right of [latex]4[/latex] on the [latex]y\text{-axis}[/latex], so the [latex]y\text{-coordinate}[/latex] of the point is [latex]4[/latex]. The coordinates of the point are [latex]\left(2,4\right)[/latex].
Point D is below [latex]4[/latex] on the [latex]x-\text{axis}[/latex], so the [latex]x\text{-coordinate}[/latex] of the point is [latex]4[/latex]. The point is to the right of [latex]-4[/latex] on the [latex]y\text{-axis}[/latex], so the [latex]y\text{-coordinate}[/latex] of the point is [latex]-4[/latex]. The coordinates of the point are [latex]\left(4,-4\right)[/latex].
try it
[ohm_question]146915[/ohm_question]example
Name the ordered pair of each point shown:
Answer: Solution
| Point A is on the x-axis at [latex]x=-4[/latex] . | The coordinates of point A are [latex]\left(-4,0\right)[/latex] . |
| Point B is on the y-axis at [latex]y=-2[/latex] | The coordinates of point B are [latex]\left(0,-2\right)[/latex] . |
| Point C is on the x-axis at [latex]x=3[/latex] . | The coordinates of point C are [latex]\left(3,0\right)[/latex] . |
| Point D is on the y-axis at [latex]y=1[/latex] . | The coordinates of point D are [latex]\left(0,1\right)[/latex] . |
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[ohm_question]146919[/ohm_question]Licenses & Attributions
CC licensed content, Original
- Question ID 146919, 146915, 146888, 146887, 146886, 146885, 146883. Authored by: Lumen Learning. License: CC BY: Attribution.
CC licensed content, Specific attribution
- Prealgebra. Provided by: OpenStax License: CC BY: Attribution. License terms: Download for free at http://cnx.org/contents/[email protected].
