Suppose gradf$(x,y)=3ysin(xy)vec(i)+3xsin(xy)vec(j),$vec$(F)=$gradf$(x,y),$ and $C$ is the segment of the parabola $y=5x^2$ from the point $(3,45)$ to $(5,125).$ Then

${\displaystyle \underset{C}{\overset{\phantom{}}{}}}$vec$(F)*dvec(r)=$