C0 -0rdinates

 

 

Cartesian axes

The x axis goes along horizontally.

The y axis goes vertically upwards.

They cross at the Origin,  O.

 

 

 

.

 

 

 

Co-ordinates are written inside brackets, with a comma

 Separating the x and y values. The x value comes before the y value.

 

 

 

   To read Cartesian co-ordinates:-

·       Start at zero

·       Count the number of units along.  This gives the x co-ordinate.

·       Count the number of units up.  This gives the y co-ordinate.

·       write down your numbers inside brackets, with a comma.

 

Example

 

 

A is the point ( 3, 7)

it is 3 units along, and 7 units up.

 

 

 

 

 

 

 

 

 

   To plot Cartesian co-ordinates:-

·       Start at zero

·       Count the number of units along.  This gives the x co-ordinate.

·       Count the number of units up.  This gives the y co-ordinate.

·       Put  a dot and label.

 

 

 

A is the point ( 3, 7)

it is 3 units to the right and 7 units up.

 

B is the point ( -5, -3)

it is 5 units to the left and 3 units down.

 

C is the point ( 8, -2)

it is 8 units to the right and 2 units down.

 

D is the point ( -2, 5)

it is 2 units left and 5 units up.

 

 

 

Remember

x along, y to the sky.

Wise up   ( y is up )

Along the corridor, then up the stairs

 

 

 

 

 

Polar Co-ordinates

 

 Polar co-ordinates are of the form

( radius, θ)

 

Where θ is measured in radians.