Figure 9 
Tangent vectors; \(\mathbf{r}^{\prime} (t_0)=\lim\limits_{h\rightarrow 0} \dfrac{\mathbf{r}(t_{0}+h)-\mathbf{r}(t_{0})}{h}\)
Tangent vectors; \(\mathbf{r}^{\prime} (t_0)=\lim\limits_{h\rightarrow 0} \dfrac{\mathbf{r}(t_{0}+h)-\mathbf{r}(t_{0})}{h}\)