Materi 2 Koordinat Kartesius

Cartesian Coordinates

Materi MK Matematika I

Dosen Pengampu: Ir. Anis Siti Nurrohkayati, S.T., M.T

Introduction

Cartesian coordinates can be used to pinpoint where we
are on a map or graph.

Using Cartesian Coordinates we mark a point on a graph
by how far along and how far up it is:

Introduction

The point (10,5) is 10 units along, and 5 units up.

0

1

2

3

4

5

6

0

2

4

6

8

10

12

They are also
called Rectangular
Coordinates because it
is like we are forming a
rectangle.

X and Y Axis

• The left-right (horizontal) direction is commonly called X.
• The X axis runs horizontally through zero.

X

• The up-down (vertical) direction is commonly

called Y.

• The Y axis runs vertically through zero.

Y

Direction

• As X increase, the point moves

further right. When X decrease, the
point moves further to the left.

• Negative X goes to the left.
• As Y increase, the point moves

further up. When Y decrease, the
point moves further down.

• Negative Y goes down.

Writing Coordinates

• The coordinates are always written in a certain order:

• the horizontal distance first,
• then the vertical distance.

• This is called an "ordered pair" (a pair of numbers in

a special order)

• And usually the numbers are separated by a comma,

and parentheses are put around the whole thing like
this:

• (7,3) means 7 units to the right, and 2 units up

The Origin; Abscissa and Ordinate

• The point (0,0) is given the special name "The Origin",

and is sometimes given the letter "O".

• Abscissa: the horizontal ("x") value in a pair of

coordinates: how far along the point is

• Ordinate: the vertical ("y") value in a pair of

coordinates: how far up or down the point is

What is Cartesian?

• They are

called Cartesian because the
idea was developed by the
mathematician and
philosopher Rene
Descartes who was also known
as Cartesius.

• He is also famous for saying "I

think, therefore I am".

Four Quadrants

• When we include

negative values, the x
and y axes divide the
space up into 4 pieces:

Quadrants I, II,

III and IV

• (They are numbered in

a counterclockwise directi
on)

3 Dimensions

• Cartesian coordinates can be used for locating points in

3 dimensions as in this example:

In fact, this idea can be continued into four
dimensions and more

Terimakasih

Referensi:
https://www.mathsisfun.com/data/cartesian-coordinates.html