(Solved): Find a tangent vector at \( t=\frac{\pi}{2} \) for the following parameterized curve. \[ \mathbf{r} ...

Find a tangent vector at \( t=\frac{\pi}{2} \) for the following parameterized curve. \[ \mathbf{r}(t)=\langle t, \sin 6 t, 2 \cos t\rangle \] Choose the correct answer below. A. \( \langle 1,0,0\rangle \) B. \( \left\{\frac{\pi}{2},-1,0\right\} \) C. \( \langle 1,-6,-2\rangle \) D. Since \( r^{\prime}(t)=0 \), there is no tangent vector.