Does this Series Converge or Diverge, by which test(s)?

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Homework Statement



Does The series Ʃ (2n)!/(n-1)*3^n converge or diverge?

(Starts at n=2 to infinity )

Homework Equations





The Attempt at a Solution



I tried the ratio test and nth-term test, and ended up with infinity, I'm not sure about it's convergence.
 
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Alexc475 said:

Homework Statement



Does The series Ʃ (2n)!/(n-1)*3^n converge or diverge?

(Starts at n=2 to infinity )

Homework Equations





The Attempt at a Solution



I tried the ratio test and nth-term test, and ended up with infinity, I'm not sure about it's convergence.

If the ratio you get from the ratio test goes to infinity, then the series diverges.
 
Dick said:
If the ratio you get from the ratio test goes to infinity, then the series diverges.

Ohh no wonder. Thank you! I forgot that if L>1 (L being the limit) that it converges
 
Alexc475 said:
Ohh no wonder. Thank you! I forgot that if L>1 (L being the limit) that it converges
No, if L > 1, it diverges.
 
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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