[tex]\bf \begin{array}{lllll}
&x_1&y_1\\
% (a,b)
&({{ 1}}\quad ,&{{ \frac{1}{2}}})\quad
% (c,d)
\end{array}
\\\quad \\
% slope = m
slope = {{ m}}= \cfrac{rise}{run} \implies\cfrac{1}{2}
\\ \quad \\
% point-slope intercept
y-{{ y_1}}={{ m}}(x-{{ x_1}})\qquad
\begin{array}{llll}
\textit{plug in the values}\\
\end{array}\\
\qquad \uparrow\\
\textit{point-slope form}[/tex]
