(Solved): Find the principal unit normal vector to the curve at the specified value of th \[ \mathbf{r}(t)=9 ...

Find the principal unit normal vector to the curve at the specified value of th \[ \mathbf{r}(t)=9 \cos (2 t) \mathbf{i}+9 \sin (2 t) \mathbf{j}+9 \mathbf{k}, \quad t=\frac{\pi}{4} \] \[ \mathrm{N}\left(\frac{\pi}{4}\right)= \] \( 0 / 2 \) Points] Find the tangential and normal components of acceleration at the given time \[ \mathbf{r}(t)=\sin (t) \mathbf{i}-3 t \mathbf{j}+\cos (t) \mathbf{k}, \quad t=\frac{\pi}{4} \] \[ a_{T}= \]