Is there a smooth covector field on

that is exact and vanishes at exactly one point?
I think the answer is no...
in case of exact field we have

for some smooth function on

... it vanishes at some point

when partial derivatives of

at p are equal to zero (in some chart containing

).
..is it correct to say that if we consider stereographic coordinates on

then for any point

where

vanishes it will also vanish at point

??