Hello, I have a question about conservative forces. 'A particle is moving according to r = a cos(wt) i + b sin(wt) j, where a and b are constants, w is angular velocity, r is a vector and i,j are unit vectors that point the same direction as the x and y axes, respectively. I am asked to determine if this force is conservative or not.' Sure, the orbit of the particle is ellipse, but how can I determine if this force is conservative or not? Please, help me.