- #1
The_Iceflash
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Homework Statement
Ok. For this sequence: [tex]a_{n} = n^2\left|cosn\pi\right|[/tex], Show/Prove that [tex]a_{n} \rightarrow\infty[/tex]
Homework Equations
N/A
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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