Hey,
here is the formal question.
M is a riemannian sub-manifold in N. a,b are vector fields such that for each p\inM, ap,bp \in TpM \subset TpN
prove
\nablaMba = pr(\nablaNba)
where pr is the projection funtion pr:TpN\rightarrowTpM
and \nablaN and \nablaM are the covariant derivative...