I'm reviewing for my final and there is a question I cant seem to solve. If anyone could help me with it I would appreciate it very much.(adsbygoogle = window.adsbygoogle || []).push({});

A ruled surface has the parameterization of the form:

x(s,t) = A(s) + tB(s)

where A(s) is unit speed, |B(s)| = 1.

Show that: K<or= to 0.

So, my first though was to just calculate the g_ij's and then just find its determinant and plug it into the equation:

K = (R_1L21 * g_L2)/g ~ Summed for L = 1,2

But after calculate some of the metric coeff's i'm not sure it will work out all that well. Any help would be appreciated.

' = d/ds

g_12 = g_21 = <A',B>

g_11 = 1 + 2t<A',B'> + t^2<B',B'>

g_22 = 1

**Physics Forums | Science Articles, Homework Help, Discussion**

Dismiss Notice

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Gauss Curvature

Loading...

**Physics Forums | Science Articles, Homework Help, Discussion**