(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Ok. For this sequence: [tex]a_{n} = n^2\left|cosn\pi\right|[/tex], Show/Prove that [tex]a_{n} \rightarrow\infty[/tex]

2. Relevant equations

N/A

3. The attempt at a solution

I have to manipulate the statement to show that

[tex]n^2\left|cosn\pi\right| > ?[/tex]

I'm having trouble making a statement that's smaller. If it was a fraction I could do it:

Ex: Manipulating [tex]\frac{n^3}{n^2+2}[/tex] gets

[tex]\frac{n^3}{n^2+2} > \frac{n^3}{n^2+n^2} = \frac{n^3}{2n^2} = \frac{n^3}{2}[/tex]

I replace 2 with n^2 to make the denominator bigger thus making it smaller. I somehow have to do something like that with the sequence given but I'm not sure how.

Any help is appreciated.

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# Homework Help: Infinite Limit question

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