Chapter 12.4, Problem 3ES

In the marginal note associated with Example 8 of Section 12.3, we observed that a line $\text{r}={\text{r}}_0+t\text{v}$ can be parametrized in terms of an arc length parameter s with reference point ${\text{r}}_{\text{0}}$ by normalizing v. Use this result to show that the tangent line to the graph of $\text{r}\left(t\right)$ at the point $t_0$ can be expressed as $\text{r}=\text{r}\left(t_0\right)+sT\left(t_0\right)$ where s is an arc length parameter with reference point $\text{r}\left(t_0\right).$