01.07.2014 Views

14.4. Normal Curvature and the Second Fun- damental Form

14.4. Normal Curvature and the Second Fun- damental Form

14.4. Normal Curvature and the Second Fun- damental Form

SHOW MORE
SHOW LESS

Create successful ePaper yourself

Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.

Observe that −→ n g is <strong>the</strong> unit normal vector to <strong>the</strong> curve C<br />

contained in <strong>the</strong> tangent space T p (X) at p.<br />

<strong>Normal</strong> <strong>Curvature</strong> . . .<br />

Geodesic <strong>Curvature</strong> . . .<br />

If we use <strong>the</strong> frame ( −→ t , −→ n g , N), we will see shortly that<br />

X ′′ (s) = κ −→ n can be written as<br />

κ −→ n = κ N N + κ g<br />

−→ ng .<br />

The component κ N N is <strong>the</strong> orthogonal projection of κ −→ n onto<br />

<strong>the</strong> normal direction N, <strong>and</strong> for this reason κ N is called <strong>the</strong><br />

normal curvature of C at p.<br />

The component κ g<br />

−→ ng is <strong>the</strong> orthogonal projection of κ −→ n onto<br />

<strong>the</strong> tangent space T p (X) at p.<br />

Home Page<br />

Title Page<br />

◭◭ ◮◮<br />

◭<br />

◮<br />

Page 688 of 711<br />

Go Back<br />

Full Screen<br />

We now show how to compute <strong>the</strong> normal curvature. This will<br />

uncover <strong>the</strong> second fun<strong>damental</strong> form.<br />

Close<br />

Quit

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

Saved successfully!

Ooh no, something went wrong!