 I'm Lucy and in this video we're going to learn all about the basics of graphs, what are axes, how do coordinates work and what are quadrants. Starting from the beginning notice how the horizontal axis is called x and the vertical axis is called y and they all start at zero here in the middle which is known as the origin with the positive numbers going in these directions and the negative numbers going backwards and downwards it's really important to remember that the x-axis is the horizontal one just think x is across so x goes across so now we know all about how the axes work let's make use of them so coordinates are written as two numbers separated by a comma and with brackets around the first number is the x coordinate and the second number is the y coordinate this is easy to remember because the first numbers are long and the second one is up or down because you have to go along the corridors before you can go up the stairs or you might just like to think about alphabetically x comes before y so what are the coordinates of this point pause the video have a think and click play when you're ready to check it is one four because it is one along from the origin and four up where would negative four six go on the grid pause the video have a think and click play when you're ready to check did you think it was here so it's negative four in this direction and six squares up coordinates are really useful for maps the GPS systems for computer games the pixels on screens and these are known as cartesian coordinates in honor of the man who developed them in the 17th century notice how the graph is divided into four sections these are called quadrants notice how they're numbered in an anti-clockwise direction starting at one and going around to four so there we have axes coordinates and quadrants in the next video we're going to look at horizontal and vertical lines and two important diagonal lines