# General Form of the Equation of a Line

The general equation or standard equation of a straight line is given by

In this case, and are constants and either or .

__CASE – I__**: **If or , then the general equation or standard equation of straight line can be written in the following form:

This is the equation of a straight line parallel to the -axis. Thus, the line is parallel to the -axis if .

__CASE – II__**: **If or , then the general equation or standard equation of straight line can be written in the following form:

This is the equation of a straight line parallel to the -axis. Thus, the line is parallel to the -axis if .

__CASE – III__**: **If or , then the general equation or standard equation of straight line can be written in the following form:

This is the equation of a straight line in slope intercept form with a slope of and a -intercept of .