1. René Descartes
31 March 1596 – 11 February 1650

2. Why am I showing you a picture of
Rene Descartes??

4. Rene Descartes invented a way to
combine geometry with algebra.
ax 2
+b 2
y
=z
c
=
b
x- +
y+ a
z=
45
Cartesian
Coordinates

5. He started with a grid, similar to
what map makers use.

6. He called the main lines axis,
and named them x and y.
y
x

7. He said any point can be represented
as a pair of values, (x,y)
The first value, x,
will describe how
far the point will be x=- x=+
from the y axis.
Positive values go
right, negative go
left.

8. a value of x = 3
will be any point
3 units to the
right of the y
axis
a value of x = -4
will be any point
4 units to the
left of the y
axis

9. The second value, y,
will describe how y=+
far the point will be
from the x axis.
Positive values go
up, negative go y=-
down.

10. a value of y = 3 will
be any point 3 units
above the x axis
a value of y = -4 will
any point 4 units
below the x axis

11. Any single point has
1 x value and 1 y
(3,4)
value written like
this (x,y)
Point (3,4) is 3
units right and 4
units up

12. Plot the following points
A(3,2)
B(-1,3)
C(-2,-1)
D(2,-2)