数列an的通项公式为an=logn+1n+2,则它的前六项积为多少
问题描述:
数列an的通项公式为an=logn+1n+2,则它的前六项积为多少
答
an=log(n+1)(n+2)=lg(n+2)/lg(n+1)
a1*a2.*a6
=lg3/lg2*lg4/lg3*lg5/lg4.*lg8/lg7
=lg8/lg2
=3lg2/lg2
=3