## Precalculus (6th Edition) Blitzer

We know that in the rectangular system of coordinates, an ordered pair is $\left( x,y \right)$, where the number written on the left is the x coordinate and the one written on the right is the y coordinate. When the x coordinate is positive, it will be plotted on the right side of the vertical axis and when it is negative, it will be plotted on the left. Similarly, if the y coordinate is positive, it will be plotted above the horizontal axis and when it will be negative, it will be plotted below it. In order to find the ordered pair, we have to substitute different values of x and calculate for the values of y. Then, we will plot the points and join the points to form a curve.