(s, prec, rnd=round_fast)
return mpf_nthroot(s, 3, prec, rnd)
cubic root of a positive number
cubic root of a positive number
cubic root of a positive number
def mpf_cbrt(s, prec, rnd=round_fast):
    """cubic root of a positive number"""
    return mpf_nthroot(s, 3, prec, rnd)
def mpf_cbrt ( s , prec , rnd = round_fast ) : return mpf_nthroot ( s , 3 , prec , rnd )