Consider (0, b) as the point on the y-pivot whose separation from line \[\mathbf{x}/\mathbf{3}\text{ }+\text{ }\mathbf{y}/\mathbf{4}\text{ }=\text{ }\mathbf{1}\text{ }\mathbf{is}\text{ }\mathbf{4}\text{ }\mathbf{units}.\]
It very well may be composed as \[\mathbf{4x}\text{ }+\text{ }\mathbf{3y}\text{ }\text{ }\mathbf{12}\text{ }=\text{ }\mathbf{0}\text{ }\ldots \text{ }.\text{ }\left( \mathbf{1} \right)\]
By contrasting condition (1) to the overall condition of line\[\mathbf{Ax}\text{ }+\text{ }\mathbf{By}\text{ }+\text{ }\mathbf{C}\text{ }=\text{ }\mathbf{0}\] , we get
\[\mathbf{A}\text{ }=\text{ }\mathbf{4},\text{ }\mathbf{B}\text{ }=\text{ }\mathbf{3}\text{ }\mathbf{and}\text{ }\mathbf{C}\text{ }=\text{ }\text{ }\mathbf{12}\]
We realize that the opposite distance (d) of a line \[\mathbf{Ax}\text{ }+\text{ }\mathbf{By}\text{ }+\text{ }\mathbf{C}\text{ }=\text{ }\mathbf{0}\] from (x1, y1) is composed as
By cross augmentation
\[\mathbf{20}\text{ }=\text{ }\left| \mathbf{3b}\text{ }\text{ }\mathbf{12} \right|\]
We get
\[\mathbf{20}\text{ }=\text{ }\pm \text{ }\left( \mathbf{3b}\text{ }\text{ }\mathbf{12} \right)\]
Here \[\mathbf{20}\text{ }=\text{ }\left( \mathbf{3b}\text{ }\text{ }\mathbf{12} \right)\text{ }\mathbf{or}\text{ }\mathbf{20}\text{ }=\text{ }\text{ }\left( \mathbf{3b}\text{ }\text{ }\mathbf{12} \right)\]
It tends to be composed as
\[\mathbf{3b}\text{ }=\text{ }\mathbf{20}\text{ }+\text{ }\mathbf{12}\text{ }\mathbf{or}\text{ }\mathbf{3b}\text{ }=\text{ }-\text{ }\mathbf{20}\text{ }+\text{ }\mathbf{12}\]
So we get
\[\mathbf{b}\text{ }=\text{ }\mathbf{32}/\mathbf{3}\text{ }\mathbf{or}\text{ }\mathbf{b}\text{ }=\text{ }-\text{ }\mathbf{8}/\mathbf{3}\]
Henceforth, the necessary focuses are \[\left( \mathbf{0},\text{ }\mathbf{32}/\mathbf{3} \right)\text{ }\mathbf{and}\text{ }\left( \mathbf{0},\text{ }-\text{ }\mathbf{8}/\mathbf{3} \right).\]