Transcript negative, positive

Describe the location of the fly that
will appear on the screen.
Describe the location of this fly.
Now describe the location of this fly.
Which fly location was the easiest to describe?
WHY?
Did you know that this idea of locating an object using a
grid (coordinate plane) was developed by a mathematician
named Rene Descartes? He was in bed one
morning watching a fly walk across his ceiling. He wanted
to describe the exact location of the fly and he wanted to
Describe the path the fly walked. This led to the idea of
the coordinate plane!
That Descartes guy sounds
pretty interesting!
Yeah, most mathematicians are pretty
interesting!
Math is AWESOME!!
The coordinate plane is divided into four quadrants by the
x-axis and the y-axis.
x-axis
y-axis
The point where the x-axis and the y-axis intersect is called
the origin.
origin
x-axis
y-axis
We label numbers on the x and y axis the same way we
label numbers on a number line . We start at the zero.
3
2
1
-3
-2
-1
0
1
-1
-2
-3
y-axis
2
3
x-axis
The quadrants are numbered using Roman Numerals.
x-axis
y-axis
Each quadrant has specific types of points that go in it.
( negative, positive)
( positive, positive)
x-axis
( negative, negative)
( positive, negative)
y-axis
Points are located by describing their distance from the origin.
First the distance right or left of the origin is given, then the
distance above or below.
The location of a point is described
using two numbers, an x-coordinate
and a y-coordinate.
x-axis
What do you think the x-coordinate describes,
the distance right or left of the origin or the
distance up or down from the origin?
What do you think the y-coordinate describes,
the distance right or left of the origin or the
distance up or down from the origin?
y-axis
The x-coordinate and y-coordinate used to name the location
of a point are written as an ordered pair - (x, y).
This point is located
2 units to the right of
the origin and 3 units
up from the origin. So,
the ordered pair that
describes its location
is (2, 3).
3
2
ORIGIN
1
-3
-2
-1
1
-1
-2
-3
y-axis
2
3
x-axis
State the ordered pair that describes the location of each
point.
3
2
1
-3
-2
-1
1
-1
-2
-3
y-axis
2
3
x-axis
Draw an x-axis and a y-axis on a piece of graph paper. Label
both.
Label each quadrant on the coordinate plane.
Graph the following points. Write the ordered pair next to
the point.
(13, 8)
(-7, 2)
(-5, -3)
(17, -11)
(9, 2)
(0, -14)
(2, 0)
(-9, -7)