Solution
= Solution
When $F_y=0$, the <Euler-Lagrange equation> reduces immediately to $dF_{y'}/dx=0$. Therefore
$$
\boxed{F_{y'}=C.}
$$
This is conservation of the generalized momentum associated with a <cyclic coordinate>.
= Solution
When $F_y=0$, the <Euler-Lagrange equation> reduces immediately to $dF_{y'}/dx=0$. Therefore
$$
\boxed{F_{y'}=C.}
$$
This is conservation of the generalized momentum associated with a <cyclic coordinate>.