Consider the vector-valued function
$\mathbf{r}(t)=t^{2} \mathbf{i}+(t-3) \mathbf{j}+t \mathbf{k} .$
Write a vector-valued function $\mathbf{s}(t)$ that is the specified transformation of $\mathbf{r}$.
(a) A vertical translation three units upward
(b) A horizontal translation two units in the direction of the negative $x$ -axis
(c) A horizontal translation five units in the direction of the positive $y$ -axis