Compute the matrix of the second fundamental form for the following parametrised surfaces:

i).r(u,v)=a(sin(u)cos(v),sin(u)sin(v),cos(u));

ii).r(u,v)=((a+bcos(u))cos(v),(a+bcos(u))sin(v),bsin(v))(0<b<a);

iii).r(u,v)=(ucos(v),usin(v);bv);