19.02.2013 Views

regular smooth curve - Penn Math

regular smooth curve - Penn Math

regular smooth curve - Penn Math

SHOW MORE
SHOW LESS

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 a <strong>regular</strong> (<strong>smooth</strong>) <strong>curve</strong>.<br />

Then the arc length along � , starting from some<br />

point �(t0) , is given by<br />

t<br />

s(t) = �to |�'(t)| dt .<br />

Note that s'(t) = |�'(t)| � 0 , so we can invert this<br />

function to obtain t = t(s) .<br />

Then �(s) = �(t(s)) is a reparametrization of our <strong>curve</strong>,<br />

and |�'(s)| = 1.<br />

We will say that � is parametrized by arc length.<br />

7

Hooray! Your file is uploaded and ready to be published.

Saved successfully!

Ooh no, something went wrong!