Note: Either public, protected or private keyword is used in place of access_specifier term used in the above code. Example of public, protected and private inheritance in C++
The graph of a relation of the form y = 5 is a line parallel to the x-axis because the y value never changes. A line parallel to the x-axis is called a horizontal line. The graph of a relation of the form x = 5 is a line parallel to the y-axis because the x value never changes. A line parallel to the y-axis is called a vertical line. Plot the graph of each of the following relations: horizontal line, vertical line.
The y-axis on the wall is vertical but the one on the table is horizontal. In the 2-dimension case, as mentioned already, the usual designation of the vertical coincides with the y-axis in co-ordinate geometry.