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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 x_axis_rotation(theta):
 """Generates a 3x3 rotation matrix for a rotation of angle theta about the x axis. Parameters theta : float amount to rotate, in radians Returns ------- :obj:`numpy.ndarray` of float A random 3x3 rotation matrix. """

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