In mathematics, a plane is not something we see zooming around in the sky. It is a flat 2D surface. The top of your desk could be a plane, as could your wall or your roof. A number plane is created by two perpendicular lines that we call an x-axis and a y-axis.
The $x$x-axis is the horizontal line.
The $y$y-axis is the vertical line.
Where the two axes cross each other is labelled the ORIGIN. It has a zero value on both axes.
The $x$x-axis is numbered with positive numbers increasing to the right.
The $y$y-axis is numbered with positive numbers increasing vertically.
We can notice 2 things from the number plane we have created here:
So what sort of things do we need to be able to do with number planes?
Let's have a look at these worked examples.
What are the coordinates of the point shown in the number plane?
Give the coordinates in the form $\left(x,y\right)$(x,y).
In which quadrant does the point $\left(4,4\right)$(4,4) lie?
Write the coordinates of the point that is $5$5 units to the right of $\left(-3,-4\right)$(−3,−4).