[tex]g(x)=3x-x^3[/tex][tex]\text{Let the rate be r}[/tex][tex]r=\frac{g(2)-g(-1)}{2-(-1)}[/tex][tex]\begin{gathered} g(2)=3(2)-(2)^3=6-8=-2 \\ g(-1)=3(-1)-(-1)^3=-3-(-1)=-3+1=-2 \\ \Rightarrow r=\frac{-2-(-2)}{2-(-1)}=\frac{0}{2}=0 \end{gathered}[/tex]
Hence, the average rate of change is 0
