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# How would I be able to continue this root test?

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How would I be able to continue this root test?

I was originally solving for

$$\sum_{n=1}^{infinity}(((-1)^n-15/n)^n)^2$$

I am being instructed to use the root test so I set up the following:

$$\lim_{n\rightarrow infinity}$$$$((\sqrt[n]{|(-1)^n(1-(15/n)|})^n)^2$$

However I'm not sure if I can cancel out anything here. Any help?

Guest Apr 18, 2017
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$$\lim_{n\rightarrow infinity}{{(\sqrt[n]{|{(-1)}^{n}*(1-(\frac{15}{n}))|})}^{n}}^{2}= \lim_{n\rightarrow infinity}{|{(-1)}^{n}*(1-(\frac{15}{n}))|}^{2}=(\lim_{n\rightarrow infinity}{|{(-1)}^{n}*(1-(\frac{15}{n}))|})^2=1^2=1.$$

Ehrlich  Apr 18, 2017