Thank you!
We have:
\cdot d\;\vec{r}\;,\quad (\;\vec{r}=(x.y,z)\" alt="\displaystyle\int_{C} f dx + g dy + h dz=\displaystyle\int_{C} \nabla F(\;\vec{r}\\cdot d\;\vec{r}\;,\quad (\;\vec{r}=(x.y,z)\" />
Now, apply the Gradient theorem
Fernando Revilla