1. The problem statement, all variables and given/known data Find the one-dimensional particle motion in the trigonometric potential U(x) = V tan^2(a x) , V > 0 . Find the one-dimensional particle motion in the Morse potential U(x) = A(1-e^-ax)^2. 2. Relevant equations well at the moment in class our lecturer derived: T = sqrt(2m) integral(dx / sqrt[E - U(x)]) with limits x1 and x2, where the limits of integration are the limits of the motion (or turning points), given by v=0. 3. The attempt at a solution Im unsure as always as to what the answer should even look like. Well i started with lagrangian L = V-U , L = m/2 v^2 - Vtan^2(ax) and got to d/dt(dL/dv) = dL/dx, but it didnt look right and how im unsure even how to approach the problem.