1. ## Calculate a

Designate by (Un) te sequence defined by : U1=2
2Un+1=Un+1
Let (Vn) be the sequence defined by Vn=Un +a
calculate a so that the sequence (Vn) is goemetric .

2. ## Re: Calculate a

Originally Posted by lebanon
Designate by (Un) te sequence defined by : U1=2
2Un+1=Un+1
Let (Vn) be the sequence defined by Vn=Un +a
calculate a so that the sequence (Vn) is goemetric .
this equation makes no sense ... are either of the (n+1) 's supposed to be subscripts?

3. ## Re: Calculate a

1. Go back and reread the problem. What you have written is impossible.

2. Try! What do you know about geometric series? What are the first three or four values of $U_n$: $U_2$, $U_3$, $U_4$? Can you guess the general formula for $U_n$?