QuestionP57. (3 Use Stokes' Theorem to evaluate the line integral $$\oint_{\mathcal{C}}\left(-6 x^{2}+z^{2}-2 x z^{3}\right) d x+\left(-2+3 z^{2}\right) d y+\left(x^{2}-3 x^{2} z^{2}\right) d z$$ as a surface integral where $\mathcal{C}$ is the boundary of the surface with parametrization $\vec{r}(s, t)=$ $\langle s, t,-2 s-3 t+6\rangle$ where $0 \leq s \leq 1$ and $0 \leq t \leq 2$. Answer. -30