How Can the Sequence (n^2 +10)/(n^3 -10) Be Proven to Converge to 0?

  • Thread starter Thread starter transgalactic
  • Start date Start date
  • Tags Tags
    Proof
Join the discussion
Registration is free. Start your own thread to ask a follow-up.
3 replies · 2K views
transgalactic
Messages
1,386
Reaction score
0
|(n^2 +10)/(n^3 -10)<(n^2 +10)/(n^3)< ..<e

i need some (1/n)<e


??
 
Physics news on Phys.org
What's the actual question that you're asking?
 
i need to prove a convergence

i stuck on the last part
i got

n>10/(e-1)what to write about N ??
 
To show it is bounded:

0 < |(n^2 +10)/(n^3 -10)<2(n^2)/(n^2) = 2

To show it converges, try to show that the sequence is monotone, and use the fact that all bounded and monotonic sequences converge. Or, see below:


To show it converges:

[n^2(1 + 10/n^2)] / [n^2(n - 10/n^2)]

= (1 + 10/n^2) / (n - 10/n^2)

the 10/n^2 in both the numerator and denominator converge to 0 and so we have 1/n, which converges to 0 as well.
 
Last edited: