Determine this sequence increasing or decreasing

e179285
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A sequence (an) is recursively defined by a1 = 1 and
an+1 =1 /(2+an ) for all n≥1

I'll prove this sequence is convergent by monoton sequence theorem.ı can find ıt is bounded but ı cannot decide it is monoton because when ı write its terms,Its terms are increasing sometimes decreasing sometimes.

How can ı prove it is increasing or decreasing?
 
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e179285 said:
How can ı prove it is increasing or decreasing?

For what value of an would it be stationary, ie. an+1 = an?
 
Do an+1-an and you'll have to combine it into one fraction and then do some factoring and you'll see if it's decreasing or increasing.
 
Prove $$\int\limits_0^{\sqrt2/4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx = \frac{\pi^2}{8}.$$ Let $$I = \int\limits_0^{\sqrt 2 / 4}\frac{1}{\sqrt{x-x^2}}\arcsin\sqrt{\frac{(x-1)\left(x-1+x\sqrt{9-16x}\right)}{1-2x}} \, \mathrm dx. \tag{1}$$ The representation integral of ##\arcsin## is $$\arcsin u = \int\limits_{0}^{1} \frac{\mathrm dt}{\sqrt{1-t^2}}, \qquad 0 \leqslant u \leqslant 1.$$ Plugging identity above into ##(1)## with ##u...

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