Which of the following terms, when added to the Lagrangian L(x, y, \(\dot x\), \(\dot y\)) of a system with two degrees of freedom, will not change the equations of motion?
1
\(x\ddot x - y\ddot y\)
2
\(x\ddot y - y\ddot x\)
3
\(x\dot y - y\dot x\)
4
\(y{\dot x^2} + x{\dot y^2}\)