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math_grl
Apr13-11, 01:31 PM
Ok I need to know which is the right answer for evaluating the continued fraction \langle 1, 2, 1, 2, \ldots \rangle?

Here's my work:
x = 1 + \frac{1}{2+x} \Rightarrow x^2 + x - 3 = 0 and by quadratic formula, we get x = \frac{-1 \pm \sqrt{13}}{2} but we only want the positive root so I get x = \frac{-1 + \sqrt{13}}{2} for my answer but the answer given was x = \frac{1 + \sqrt{3}}{2}, so I'm confused at which it is....

Moreover, I can't seem to find any other example except for \langle 1, 1, 1, \ldots \rangle to see if I'm doing my computation right. Please help.

Petek
Apr13-11, 02:21 PM
Your equation for x is incorrect. It should be

1 + \frac{1}{2 + \frac{1}{x}}

math_grl
Apr13-11, 04:16 PM
:blushing:
that's embarassing.

Petek
Apr13-11, 09:49 PM
You'll do better next time!