Hello! I have the following vector ##\mathbf{A} = R(-\sin(\omega t)\mathbf{x}+\cos(\omega t)\mathbf{y})##, where ##\mathbf{x}## and ##\mathbf{y}## are orthogonal unit vectors (aslo orthogonal to ##\mathbf{z}##). I want to calculate ##\nabla \times \mathbf{A}##, but I am a bit confused. The curl...