For perpendicularity
[tex]\begin{gathered} \text{slope of line 1 =}\frac{-1}{slope\text{ of line 2}}_{} \\ \text{slope of line 1 = m}_1 \\ \text{slope of line 2 =m}_2 \end{gathered}[/tex][tex]\begin{gathered} \text{Hence,} \\ m_1=\frac{-1}{m_2} \end{gathered}[/tex][tex]\begin{gathered} \text{From the question} \\ m_1=\text{ }\frac{1}{4} \end{gathered}[/tex][tex]undefined[/tex]