Limit of a Sequence and Behaviour of a Sequence Q1

Limit of a Sequence and Behaviour of a Sequence Q1

TGM Original Questions

A sequence of negative numbers is defined by \({{x}_{n+1}}=-\sqrt{8+3{{x}_{n}}}\) for \(n=1\), \(2\), \(3\), …

  1. Show that \(-\frac{8}{3}<{{x}_{n}}<0\) for \(n=1\), \(2\), \(3\), …
  2. Find the exact value of \(l\), given that when \(n\to \infty \), \({{x}_{n}}\to l\).
  3. Show that \({{x}_{n+1}}^{2}-{{l}^{2}}=3\left( {{x}_{n}}-l \right)\).
  4. Show algebraically that if \({{x}_{n}} \lt l \) for some value of \(n\), then \({{x}_{n+1}} \gt l\).

Video Solution:

Video Solution

Video solution locked

A free account saves your progress; this video needs a course plan.

Solution:

Solution locked

680+ questions here come with free worked solutions. A free account saves your questions and progress; this one needs a course plan.

Answer:(i) \(-\frac83<x_n<0\). (ii) \(l=\frac{3-\sqrt{41}}2\). (iii) \(x_{n+1}^2-l^2=3(x_n-l)\). (iv) \(x_n<l\Rightarrow x_{n+1}>l\).

Need help? Join our JC Math tuition classes.

Learn more