Find   $\displaystyle {\tan{{\left(\frac{{u}}{{2}}\right)}}}$   if   $\displaystyle {\sin{{u}}}=-{0.423}$   and $\displaystyle {u}$ is in Quadrant-III.
$\displaystyle {\tan{{\left(\frac{{u}}{{2}}\right)}}}=$
Your answer should be accurate to 4 decimal places.