$$
\begin{array}{l}
\mathrm{z}_{1}, \mathrm{z}_{2} \mathrm{z}_{3} \text { are } 3 \text { complex numbers represented by the points } \mathrm{A}, \mathrm{B}, \mathrm{C} \text { in the Argand diagram. If the points } \mathrm{A}, \mathrm{B}, \mathrm{C} \text { are }\\
\text { collinear, prove that }\left|\begin{array}{lll}
\mathrm{z}_{1} & \overline{\mathrm{z}}_{1} & 1 \\
\mathrm{z}_{2} & \overline{\mathrm{z}}_{2} & 1 \\
\mathrm{z}_{3} & \overline{\mathrm{z}}_{3} & 1
\end{array}\right|=0
\end{array}
$$