I understand that the gradient of the unit normal vector is the curvature, but how was equation (4) in the link below derived?
Asked
Active
Viewed 30 times
0
-
Consider differentiation of $$\frac{1}{(\phi_x^2+\phi_y^2)^{1/2}}\binom{\phi_x}{\phi_y}$$ – Jean Marie Sep 26 '21 at 10:05
-
the answer for the question in the link below solve also my question, thank you. https://math.stackexchange.com/questions/28821/divergence-of-gradient-of-the-unit-normal-and-curvature-equation?noredirect=1&lq=1 – Daisuke Sugawara Sep 26 '21 at 11:19