1. The problem statement, all variables and given/known data The equation of motion for a particle of mass 1 in a quartic oscillator V(x)=0.25x^4 is x''+x^3=0. Suppose that the maximum amplitude of the oscillator is Xm(max). Find an expression for the time T that it takes to go from x=0 to x=Xm(max) and show that this time is inversely proportional to Xm(max). 2. Relevant equations Xm(max) = sqrt(x^2+mv^2/k) 3. The attempt at a solution V(x) is energy? E = 0.5mv^2 + V then d^2/dt^2(x) = -x^3 ? How to make the connection between the time T and these equations. Thanks very much.