Starting from Eq. (6.27) and similar expressions for rotations around the \(x\) and \(y\) axes, show that the generators of 3D rotations are given by Eq. (6.28). Hint: Assume group elements to be parameterized as in Eq. (3.2) with generators \(J_{a}=X_{a}\), expand expressions like Eq. (6.27) in a Taylor series, and compare with Eq. (6.6).