def vt2(rtsoll, at, atged, neigung, niveau):
    """ Return the VLsoll temp, computed by method 2.
    """
    mixedat = (atged*0.7 + at*0.3)
    dar = mixedat - rtsoll
    return niveau + rtsoll - neigung * dar * (1.4347 + 0.021 * dar + 247.9 * 10**-6 * dar * dar)