Nidhogg
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(sorry the thread title is wrong - can a mod please change it to "Limit of e^-7x cos x?")
1. Homework Statement
Find the following:
\lim_{x \rightarrow \infty} e^{-7x} \cos x
I know that [ \lim_{x \rightarrow a} f(x)g(x) ] = [ \lim_{x \rightarrow a} f(x) ] \cdot [ \lim_{x \rightarrow a} g(x)] so...
From the above equations...
[\lim_{x \rightarrow \infty} e^{-7x} \sin x] = [(\lim_{x \rightarrow \infty} e^{-7x}) \cdot (\lim_{x \rightarrow \infty} \cos x)] But this limit DNE, since \lim_{x \rightarrow \infty} cos x : DNE
And yet, WebAssign tells me that DNE is wrong, and that I must use the Squeeze Theorem for this problem. Any help? My trig is a little rusty (last time I took it was 9 years ago), so any useful reminders on that front would be helpful as well. I'm taking Calc I.
1. Homework Statement
Find the following:
\lim_{x \rightarrow \infty} e^{-7x} \cos x
Homework Equations
I know that [ \lim_{x \rightarrow a} f(x)g(x) ] = [ \lim_{x \rightarrow a} f(x) ] \cdot [ \lim_{x \rightarrow a} g(x)] so...
The Attempt at a Solution
From the above equations...
[\lim_{x \rightarrow \infty} e^{-7x} \sin x] = [(\lim_{x \rightarrow \infty} e^{-7x}) \cdot (\lim_{x \rightarrow \infty} \cos x)] But this limit DNE, since \lim_{x \rightarrow \infty} cos x : DNE
And yet, WebAssign tells me that DNE is wrong, and that I must use the Squeeze Theorem for this problem. Any help? My trig is a little rusty (last time I took it was 9 years ago), so any useful reminders on that front would be helpful as well. I'm taking Calc I.