Show that the force field

$F(x,y,z)=(ycosx+z^2)i+(sinx-2)j+(2xz+1)k$

is conservative and find its potential. Using this potential function, evaluate the line integral

${\displaystyle \underset{C}{\overset{\phantom{}}{}}}F*dr$

where $C$ is the curve given by $r(t)=costi+sintj+tk,$ for $0t\frac{}{2}.$