please help me work through this its a bit complicated, thank you!

To find the speed based on the position function, you have to derivate the function in terms of time (x)
[tex]\begin{gathered} f^{\prime}(x)=v(x)=11+22cos(x) \\ \end{gathered}[/tex][tex]\begin{gathered} v(x)=0=11+22cos(x) \\ -11=22cos(x) \\ -0.5=cos(x) \\ x=\frac{2}{3}\pi \end{gathered}[/tex][tex]\begin{gathered} f(x)=11x+22sin(x) \\ f(x)=11(\frac{2}{3}\pi)+22sin(\frac{2}{3}\pi) \\ f(x)=\frac{22}{3}\pi+19.0526 \\ f(x)=42.09m \end{gathered}[/tex]