Finding the K for the limit of a sequence

  • Thread starter Thread starter Design
  • Start date Start date
  • Tags Tags
    Limit Sequence
Join the discussion
Registration is free. Ask a follow-up in this thread, or start your own.
2 replies · 2K views
Design
Messages
62
Reaction score
0

Homework Statement


Let {xk} = 3k+4/k-5; then lim k-> infinity {xk} = 3. Given E > 0 , find an integer K so that |{xk}-3|<E when k>K

The Attempt at a Solution



| 3k+4/k-5 - 3| < E
| 3k+4/k-5 | < E + 3

Now I don't know how to isolate the left part to a single k to find the value of k and know the value of K.
 
Physics news on Phys.org
Don't add 3 to both sides- instead, combine into a single fraction

[tex]\left|\frac{3k+4}{k-5}-3\right|=\left|\frac{3k+4-3(k-5)}{k-5}\right|=\left|\frac{19}{k-5}\right|<E[/tex]