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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 separation_cos_angle(lon0, lat0, lon1, lat1):
 """Evaluate the cosine of the angular separation between two direction vectors."""

    return (np.sin(lat1) * np.sin(lat0) + np.cos(lat1) * np.cos(lat0) *
            np.cos(lon1 - lon0))