regular smooth curve - Penn Math
regular smooth curve - Penn Math
regular smooth curve - Penn Math
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
Let �: I � R 3 be parametrized by arc length, and<br />
let T(s) be the unit tangent vector along � .<br />
If the curvature �(s) � 0 , then we also have the<br />
principal normal vector N(s) at �(s) .<br />
In that case, define the binormal vector B(s) to � at s<br />
by the vector cross product,<br />
B(s) = T(s) � N(s) .<br />
Problem 10. Show that B'(s) is parallel to N(s) .<br />
13