## The Lesson

The Cartesian coordinates of a point can be read off from a graph.## How to Read Off the Cartesian Coordinates of a Point

Reading off the Cartesian coordinates of a point is easy.## Question

What are the Cartesian coordinates of the point shown on the graph below.## Step-by-Step:

# 1

Read off how far

**across**the point is along the horizontal x-axis. We see that the point is**2**units along the x-axis.**2 is the x-coordinate of the point**.**Note:**The x-axis is labelled with numbers (0, 1, 2, 3...) so you can measure how far across the point is.# 2

Read off how far

**up**the point is along the vertical y-axis. We see that the point is**4**units up the y-axis.**4 is the y-coordinate of the point**.**Note:**The y-axis is labelled with numbers (0, 1, 2, 3...) so you can measure how far up the point is.# 3

Write down the Cartesian coordinates as a pair of numbers in brackets, separated by a comma.
The x-coordinate (

**2**) found in**Step 1**goes on the left. The y-coordinate (**4**) found in**Step 2**goes on the right.## Answer:

## Beware

## Positive and Negative Coordinates

The pair of numbers in Cartesian coordinates the can be positive and negative.- The x-axis is labelled with positive numbers to the right of the y-axis and negative numbers to the left.
- The y-axis is labelled with positive numbers above the y-axis and negative numbers below.

- left, the x-coordinate is negative.
- right, the x-coordinate is positive.

- above, the y-coordinate is positive.
- below, the y-coordinate is negative.

Look at which quadrant a point is in to decide the sign of each coordinate.