# Curvature

• March 23rd 2011, 12:37 PM
Mathwizz
Curvature
I have to find the curvature of the curve with the equation (4sint)i+(4sint)j+(4cost)k. I use the magnitude of r'xr'' over the magnitude of r'^3. Nothing cancels out for me. Can anybody help??
• March 23rd 2011, 01:00 PM
Plato
Quote:

Originally Posted by Mathwizz
I have to find the curvature of the curve with the equation (4sint)i+(4sint)j+(4cost)k. I use the magnitude of r'xr'' over the magnitude of r'^3. Nothing cancels out for me. Can anybody help??

If "Nothing cancels out", then how can anyone help?

What did you get for $r'\times r''~?$

I get $<-16,16,0>.$