Pre-Algebra › Graphing Points
Write the ordered pair of points a, b, and c.
An ordered is always written in the following format:
where x is the position on the x-axis, and y is the position on the y-axis.
If we look at point a, we find where it falls on the x-axis. We can see that it's position on the x-axis is 1. Then, we see where it falls on the y-axis. It's position on the y-axis is 4. So, we can write the ordered pair for point a as
We will do the same for b. The position of point b on the x-axis is -5. The position of point b on the y-axis is 2. So, we can write the ordered pair for point b as
And finally for c. The position of point c on the x-axis is zero. The position of point c on the y-axis is -5. So, we can write the ordered pair of point c as
Determine the quadrant in which the point (-5,-3) lies.
Quadrant III
Quadrant I
Quadrant II
Quadrant IV
The point lies on an axis.
The point given in the problem is expressed as an ordered pair in the form . The number in the place of the
is called the x-coordinate and tells how far from the origin to move horizontally, while the number in place of the
is called the y-coordinate and tells how far to move from the origin vertically. The coorinate plane (the set of axes we graph points on) is divided into four regions (or quadrants) by the x-axis and y-axis. The top right region is Quadrant I, the top left region is Quadrant II, the bottom left region is Quadrant III, and the bottom right region is Quadrant IV.
Going back to our x-coordinate and y-coordinate, a postive x-coordinate means we move right from the origin the same number of units as the value. A negative x-coordinate means we move left from the origin. With y-coordinates, a positive value means we move up, while a negative value means we move down the indicated number of units. Since the ordered pair given in the problem is , our x-coordinate is
and our y-coordinate is
. That means we should move left from the origin five units and then down three units. The resulting plotted point is shown.
Having plotted the point we can clearly see that we are in Quadrant III, giving us the correct answer. In general, we can actually determine the quadrant of a point without plotting if we keep some general rules in mind. If the x- and y-coordinates are both positive, we are in Quadrant I. If the x-coordinate is negative while the y-coordinate remains positive, we are in Quadrant II. If both coordinates are negative, we are in Quadrant III. Finally, if the x-coordinate is positive while the y-coordinate is negative, we are in Quadrant IV. If either of the coordinates happens to be zero, our point will lie on one of the axes.
In which quadrant or on which axis will you find the point ?
Quadrant III
Quadrant I
Quadrant II
Quadrant IV
The -axis
By definition, a point with a negative -coordinate and a negative
-coordinate lies in Quadrant III on the coordinate plane.
Find the midpoint of the following points:
(-5, 6) and (1, 2)
The midpoint formula is
where and
are the points given. So, using the points
(-5, 6) and (1, 2) we can substitute into the midpoint formula and get
Therefore, the midpoint is (-2, 4).
In which quadrant or on which axis will you find the point ?
The -axis
The -axis
Quadrant I
Quadrant II
Quadrant III
The point does not move in any direction on the
-axis, but does move
units up on the
-axis. Therefore, the point is located only on the
-axis.
In which quadrant or on what axis will you find the point ?
Quadrant II
Quadrant I
Quadrant III
Quadrant IV
The -axis
The point has a negative
coordinate and a positive
coordinate. By definition, any point on a coordinate plane with these characteristics is located in Quadrant II.
The point is on the graph of the line
. Evaluate
.
Substitute for
and 8 for
, and solve for
:
Which quadrant does the coordinates belong to?
When looking at a coordinate plane, draw the letter C in there making sure you connect all four quarters of the grid. The C should start in the top right corner, move to the top left, then bottom left, then finish in the bottom right corner.
The quadrants start with and finish with
.
Therefore the coordinates means
to the right and
down which would place the coordinates in quadrant 4.
Which of the following points is in Quadrant II on the coordinate plane?
All points in Quadrant II have negative -coordinates and positive
-coordinates. The only answer that fulfills these criteria is
.
Which of the following is not a point on the graph of the equation ?
For each of the five choices, substitute the coordinates for and
in that order, and test the validity of the resulting equation. Below is the proof that
is on the graph:
:
This is true, so is on the graph.
The points ,
, and
can all be proved by the same procedure to be part of the graph.
However, we can prove that is not on the graph by the same procedure:
This is false, so is proved to be not on the graph. This is the correct choice.