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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def Rz_matrix(theta):
 """Rotation matrix around the Z axis"""

    return np.array([
        [np.cos(theta), -np.sin(theta), 0],
        [np.sin(theta), np.cos(theta), 0],
        [0, 0, 1]
    ])