#### Answer

$$\sqrt{10 } $$

#### Work Step by Step

Since speed is given by
\begin{align*}
\frac{d s}{d t}&=\sqrt{x^{\prime}(t)^{2}+y^{\prime}(t)^{2}}\\
&=\sqrt{ \frac{4t^2}{(t^2+1)^2}+9t^4 }
\end{align*}
Then
\begin{align*}
\frac{d s}{d t}\bigg|_{t=1} &=\sqrt{ \frac{4 }{(2)^2}+9 } \\
&=\sqrt{10 }
\end{align*}