等差数列{an}的公差d>0,其前n项和为Sn,满足S90,则n=____时,Sn最小.
等差数列{an}的公差d>0,其前n项和为Sn,满足S90,则n=____时,Sn最小.
已知等差数列{an}的公差d>0,其前n项和为sn,满足S90,则n=多少时,sn最小
已知等差数列an公差d>0,前n项和为sn若s7=s11求当n为何值时sn最小
高中数学有关数列、极限的题:设等差数列{an}的公差d=2,前n项的和为sn,则lim(an^-n^0/sn=
记数列{an}的前n项和为Sn,若{Sn/an}是公差为d的等差数列,则{an}为等差数列的充要条件是d=?
设Sn为等差数列{an}的前n项和,若a1=1,公差d=2,Sn+2-Sn=36,则n=( )
数列an是公差d不等于0的等差数列,其前n项和为Sn,且
等差数列{an}的前项和为Sn,已知S90,则数列的前n项和中,n是多少时取最小值
已知等差数列{an}中,公差d>0,其前n项和为sn,且满足a2a3=45,a1+a4=14
已知等差数列{an}中,公差d>0,其前n项和为Sn,且满足a2×a3=45,a1+a4=14
已知等差数列{an}中,公差d>0,其前n项和为Sn,且满足:a2*a3=45,a1+a4=14
已知等差数列{an}中,公差d>0,其前n项和为Sn,且满足a2*a4=45,a1+a5=14