- #1
flyingpig
- 2,579
- 1
Homework Statement
This is supposed to be really easy, but I don't think my answer is good
Consider this
[tex]\sqrt{1 + \sqrt{1 + \sqrt{1 + ...}}}[/tex]
I was hinted that [tex]a_{n + 1} = \sqrt{1 + a_n}[/tex] for all n ≥ 0 and I am supposed to show that the sequence convergees
The Attempt at a Solution
Am I suppose to use [tex]a_{n +1}[/tex] converges or [tex]a_n[/tex]?
Since the nested radicals go on to infinity, wouldn't it be better to write it as
[tex]a_n = \sqrt{1 + a_n}[/tex]
So that
[tex]a^2 _n = 1 + a_n[/tex]
We get a quadratic and solve (on Maple) we get
[tex]\frac{1}{2}(\sqrt(5) + 1)[/tex]
I rejected negative root because there is no way a negative root can occur in this sequence (we are just adding positive numbers and rooting it (I hope that's a word))