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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 Rx_matrix(theta):
 """Rotation matrix around the X axis"""

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