Find all positive integers n such that n^2
+ 1 is divisible by n+ 1. Choose the correct choice from the following options:  A) 1  B) 2  C) 3  D) 4  E) 5
There is only one such positive integer : n = 1.   In fact, n^2+1= n(n+1)-(n-1);   thus, if n+1|n^2+1, then n+1|n-1 which for positive integer n is possible only if n-1 = 0,   hence if n = 1.   1nswer is 1
<result>A</result>
Find all positive integers n such that n^2
+ 1 is divisible by n+ 1.