We have:
$$F(u,v)=\int_0^v\frac{1-cos(ut)}{t} dt $$
Find $$F_u$$ and $$F_v$$
EDIT (solution):
$$ F_u=\int_0^v \frac{\partial}{\partial u} \frac{-cos(ut)}{t}dt = \int_0^v sin(ut) dt = \frac{-cos(uv)}{u}-\frac{(-cos(0)}{u}=\frac{1-cos(uv)}{u}$$
$$ F_v = \frac{1-cos(uv)}{v} $$ comes from the second theorem of calculus
We have
$F_v(u,v)= \frac{1-cos(uv)}{v}$ (why ??)
and
$F_u(u,v)=\int_0^v \frac{\partial}{\partial u}(\frac{1-cos(ut)}{t}) dt$
Now show that $F_u(u,v)= \frac{1-cos(uv)}{u}$