SOLUTION: Please find the limit of the following sequence as n goes to infinity: {{{n/(n^2+1) +n/(n^2+4)+ n/(n^2+9)}}}+...+ {{{n/(n^2+(n-1)^2)+1/(2n)}}}. Thank you!

Algebra ->  Sequences-and-series -> SOLUTION: Please find the limit of the following sequence as n goes to infinity: {{{n/(n^2+1) +n/(n^2+4)+ n/(n^2+9)}}}+...+ {{{n/(n^2+(n-1)^2)+1/(2n)}}}. Thank you!      Log On


   



Question 1103595: Please find the limit of the following sequence as n goes to infinity:
n%2F%28n%5E2%2B1%29+%2Bn%2F%28n%5E2%2B4%29%2B+n%2F%28n%5E2%2B9%29+...+ n%2F%28n%5E2%2B%28n-1%29%5E2%29%2B1%2F%282n%29.
Thank you!

Found 2 solutions by math_helper, robertb:
Answer by math_helper(2461) About Me  (Show Source):
You can put this solution on YOUR website!
Sorry, not a closed form solution, but some values as n gets "large"…

Let +S%5Bn%5D+ = Partial sum n, +n%3E=+1+

+S%5B1%5D+=+1%2F2+=+0.5+
+S%5B2%5D+=+0.65+
+S%5B3%5D+=+0.6974359+
: : :
+S%5B1000%5D+=+0.7851481+
: : :
+S%5B10000%5D+=+0.7853732+
: : :
+S%5B100000%5D+=+0.7853957+
: : :
+S%5B1000000%5D+=+0.7853979+
——————————
Values found using a Perl one-liner (if you have Perl installed, edit the value of $m to set the max value)

perl -e '$m=1000000; for($i=0, $s=0; $i<$m; $i++) { $s += $m/($m*$m+($i+1)*($i+1)); }; print "Sum = $s\n";'
Sum = 0.785397913397392

Answer by robertb(5830) About Me  (Show Source):