The function $\displaystyle {f{{\left({x}\right)}}}=-{2}{x}^{{3}}+{4.38}{x}^{{2}}+{109.8162}{x}+{0.76}$
is increasing on the open interval ( , ).

It is decreasing on the open interval ( $\displaystyle -\infty$, ) and the open interval ( , $\displaystyle \infty$ ).

The function has a local maximum at .