1. The problem statement, all variables and given/known data Position of particle is given by: x(t) = 5 cos (3t +2) At what time after t = 0 is the particle at the equilibrium position? 2. Relevant equations 3. The attempt at a solution I understand the equilibrium position to be the point where x(t) = 0 since x(t) is thedisplacement from the equilibrium position is it not? But when i re-arrange for t, i get t = -0.14s, negative? Just doesn't seem right what am I doing wrong.