To understand the definition of the binormal vector and its role in the Frenet frame.
Subsection5.10.1The Binormal Vector
This lesson defined the binormal Vector as the third basis vector in the TNB or Frenet frame. The discussion of the binormal vector focuses on the binormal vector as being orthogonal to the unit tangent and the unit normal vector. Further the binormal is described as the direction for the axis of rotation given by the osculating circle (defined in the curvature lesson).