Normal Unit Vector

Topics: Vector

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(definition)

Given $r(t)$ a vector-valued function and $T(t)$ its tangent unit vector, we define the normal unit vector $N(t)$ as:

$$N(t):=\frac{T^{\prime }(t)}{\Vert T^{\prime }(t)\Vert }$$

…given $\Vert T^{\prime }(t)\Vert \ne 0$, of course.