Given:
The lines are \[\surd \mathbf{3x}\text{ }+\text{ }\mathbf{y}\text{ }=\text{ }\mathbf{1}\text{ }\mathbf{and}\text{ }\mathbf{x}\text{ }+\text{ }\surd \mathbf{3y}\text{ }=\text{ }\mathbf{1}\]
Along these lines, \[\mathbf{y}\text{ }=\text{ }-\text{ }\surd \mathbf{3x}\text{ }+\text{ }\mathbf{1}\text{ }\ldots \text{ }\left( \mathbf{1} \right)\] and
\[\mathbf{y}\text{ }=\text{ }-\text{ }\mathbf{1}/\surd \mathbf{3x}\text{ }+\text{ }\mathbf{1}/\surd \mathbf{3}\text{ }\ldots \text{ }.\text{ }\left( \mathbf{2} \right)\]
Slant of line (1) is m1 = – √3, while the incline of line (2) is \[\mathbf{m2}\text{ }=\text{ }-\text{ }\mathbf{1}/\surd \mathbf{3}\]
Let θ be the point between two lines
Along these lines,
\[\mathbf{\theta }\text{ }=\text{ }\mathbf{30}{}^\circ \]
∴ The point between the given lines is either 30° or \[\mathbf{180}{}^\circ -\mathbf{30}{}^\circ \text{ }=\text{ }\mathbf{150}{}^\circ \]