Equation of Lines Parallel to Axes

(i) Equation of a Line Parallel to the X-Axis:
Consider that l is the straight line which is passing through the point A\left( {0,b} \right) and is parallel tothe X-axis because this point lies on the Y-axis and any point on the Y-axis whose values of x are zero.


line-equation-parallel-axes

Then the equation of a line parallel to the X-axis is given by

\boxed{y = b}

(ii) Equation of a Line Parallel to the Y-Axis:
Consider that l is the straight line which is passing through the point B\left( {a,0} \right) and is parallel to the Y-axis, because this point lies on the X-axis and any point on the X-axis whose values of y are zero.


line-equation-parallel-axes-2

Then the equation of a line parallel to the Y-axis is given by

\boxed{x = a}