已知数列{an}的首项a1=5,前n项和为Sn, 且Sn+1=2Sn+n+5(n
问题:
已知数列{an}的首项a1=5,前n项和为Sn,
且Sn+1=2Sn+n+5(n∈N*).
(Ⅰ)证明数列{an+1}是等比数列;
(Ⅱ)令f(x)=a1x+a2x2+…+anxn,求函数f(x)在点x=1处的导数f'(1).
已知数列{an}的首项a1=5,前n项和为Sn,
且Sn+1=2Sn+n+5(n∈N*).
(Ⅰ)证明数列{an+1}是等比数列;
(Ⅱ)令f(x)=a1x+a2x2+…+anxn,求函数f(x)在点x=1处的导数f'(1).