# couples of problems related to Gauss flow and vector analysis

the surface $$S$$ is given by $$r$$ (R,$$theta$$) = (r $$cos theta$$)$$i$$+ (r $$sin theta$$)$$j$$+ $$theta k$$. (0 <= r <= a, 0 <=$$theta$$<=$$frac { pi} {2}$$ ) if the vector feild $$A$$ is given by $$A$$= x$$i$$+ y$$j$$++ z$$k$$,

1. Get the normal unit vector $$n$$ of $$S$$

2.évaluer $$int_ {S} A cdot n$$ and $$int_ {S} left ( bigtriangledown times A right) cdot n dS$$

I am new in vector analysis, any index would be appreciated.