SOLUTION:
Given that line passing through (1, 2) making an angle 30° with y – axis.
Angle made by the line with x – axis is (90° – 30°) = 60°
∴ Slope of the line, m = tan 60°
= √3
So, the equation of the line passing through the point (x1, y1) and having slope ‘m’ is
\[\begin{array}{*{35}{l}}
y\text{ }-\text{ }{{y}_{1}}~=\text{ }m\text{ }\left( x\text{ }-\text{ }{{x}_{1}} \right) \\
\left( {{x}_{1}},\text{ }{{y}_{1}} \right)\text{ }=\text{ }\left( 1,\text{ }2 \right)\text{ }and\text{ }m\text{ }=\text{ }\surd 3 \\
\Rightarrow ~y\text{ }=\text{ }2\text{ }=\text{ }\surd 3\left( x\text{ }-\text{ }1 \right) \\
\Rightarrow ~y\text{ }-\text{ }2\text{ }=\text{ }\surd 3x\text{ }-\text{ }\surd 3 \\
\Rightarrow \text{ }y\text{ }\text{ }-\surd 3x\text{ }+\text{ }\surd 3\text{ }-\text{ }2\text{ }=\text{ }0 \\
\end{array}\]