## Calculus (3rd Edition)

(a) since $\mathbf{v}=\langle 6,9\rangle=(1/2 )\langle 12,18\rangle$ then the vectors are parallel and in the same direction. (c) since $\mathbf{v}=\langle 6,9\rangle=3\langle 2,3\rangle$ then the vectors are parallel and in the same direction. (d) since $\mathbf{v}=\langle 6,9\rangle=-\langle 6,9\rangle$ then the vectors are parallel but in opposite directions. (f) since $\mathbf{v}=\langle 6,9\rangle=-(1/4)\langle -24,-36\rangle$ then the vectors are parallel but in opposite direction. The vectors in (b) and (e) are not scalar multiples of $v$, so they are neither parallel nor point in the same direction.