Current location - Training Enrollment Network - Mathematics courses - 20 14 Guangdong college entrance examination liberal arts mathematics volume 19 How to do it should be the finale of the college entrance examination, which is very difficult.
20 14 Guangdong college entrance examination liberal arts mathematics volume 19 How to do it should be the finale of the college entrance examination, which is very difficult.
This question examines the relationship between the general term and the first n terms of a series, the sum of the split terms, and the conversion method. It has a large amount of calculation and a certain degree of thinking difficulty, and belongs to a difficult problem. The answer is/exercise/math /804330, mainly because I was too lazy to do it, so I recited it directly.

Let the sum of the first n terms of the series {an} whose terms are all positive numbers be Sn and satisfy Sn? -(n? +n-3)Sn-3(n? +n)=0,n∈N*

(1) Find the value of a 1;

(2) Find the general term formula of sequence {an};

(3) It is proved that1/a1(a1+1)+1/A2 (A2+1)+... 1/3