I.12.15 Vector field circulation

Condition: Find directly and using the Stokes formula the circulation of the field \( \vec{a}=(x+3 z) \vec{\imath}+ \) \( +(2-y) \vec{\jmath}+(2 y+z) \vec{k} \quad \) by \( \quad \) contour \( \Gamma:\left\{\begin{array}{c}x^{2}+y^{2}=4 \\ 2 x-3 y-2 z=1\end{array}\right. \).