# Unit Tangent Vector Calculator

The calculator will find the unit tangent vector of the vector-valued function at the given point, with steps shown.

Enter a vector-valued function:

mathbf{vec{r}(t)}= (, , )
If you don't have the third coordinate, set it to 0.
Calculate at t=
Leave empty, if you don't need the unit tangent vector at a specific point.

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## Solution

Your input: find the unit tangent vector for $\mathbf{\vec{r}(t)}=\left(\sin{\left(t \right)}, \cos{\left(t \right)}, 7\right)$

To find the unit tangent vector, we need to find the derivative of $\mathbf{\vec{r}(t)}$ and then normalize it.

$\mathbf{\vec{r}^{\prime}(t)}=\left(\cos{\left(t \right)}, - \sin{\left(t \right)}, 0\right)$

Note. For steps in finding derivatives, see derivative calculator.

Find the norm (length) of the vector: $\lVert\mathbf{\vec{r}^{\prime}(t)}\rVert=\sqrt{\left(\cos{\left(t \right)}\right)^2+\left(- \sin{\left(t \right)}\right)^2+\left(0\right)^2}=1$

Finally, the unit tangent vector is $\mathbf{\vec{T}(t)}=\frac{\mathbf{\vec{r}^{\prime}(t)}}{\lVert\mathbf{\vec{r}^{\prime}(t)}\rVert}$

$\mathbf{\vec{T}(t)}=\frac{\left(\cos{\left(t \right)}, - \sin{\left(t \right)}, 0\right)}{1}=\left(\cos{\left(t \right)}, - \sin{\left(t \right)}, 0\right)$

Answer: $\mathbf{\vec{T}(t)}=\left(\cos{\left(t \right)}, - \sin{\left(t \right)}, 0\right)$