Hi;

Normals n are imaginary lines perpendicular to each point on a surface. If u and v gives the orientation of the surface at a given point, then the triplet (u,v,n) matches the orientation of R^3 according to the right-hand rule.

My question is given a point on the surface, how can one determine the direction of u and v? If we determine the direction of u and v then the direction of the normal vector will be determined by using the right-hand rule.

I don't know how to determine the direction of u and v at a given point on the surfcae.

Every guidance is highly appreciated.

Thank you in advance