Answer
$\left\langle\frac{3}{2}t^2, 2t^3, 9t \right\rangle.$
Work Step by Step
We have
\begin{align}
\int_{0}^{t}\left\langle 3s, 6s^2, 9 \right\rangle ds &=\left\langle \frac{3}{2}s^2, 2s^3, 9s
\right\rangle|_{0}^{t}\\
&=\left\langle \frac{3}{2}t^2, 2t^3, 9t \right\rangle-\left\langle 0, 0 ,0 \right\rangle\\
&=\left\langle\frac{3}{2}t^2, 2t^3, 9t \right\rangle.
\end{align}