Limit at Infinity: Solve Without Squeeze Theorem

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SUMMARY

The limit at infinity for the expression \(\lim_{x \to \infty} \sqrt{x}\sin\frac{1}{x}\) can be effectively solved without the Squeeze Theorem. By substituting \(t = \frac{1}{x}\), the limit transforms into \(\lim_{t \to 0} \frac{\sin t}{\sqrt{t}}\), which can be further simplified to \(\lim_{t \to 0} \frac{\sin t}{t} \times \sqrt{t}\). This approach utilizes the known limit \(\lim_{t \to 0} \frac{\sin t}{t} = 1\) and allows for a straightforward evaluation of the limit.

PREREQUISITES
  • Understanding of limits in calculus
  • Familiarity with trigonometric functions, specifically sine
  • Knowledge of limit substitution techniques
  • Basic understanding of square roots and their properties
NEXT STEPS
  • Study the properties of limits involving trigonometric functions
  • Learn about limit substitution methods in calculus
  • Explore Taylor series expansions for trigonometric functions
  • Review advanced limit techniques, including L'Hôpital's Rule
USEFUL FOR

Students preparing for calculus exams, particularly those focusing on limits and trigonometric functions, as well as educators seeking to clarify limit evaluation techniques.

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Homework Statement



[tex] \lim_{x \to \infty} \sqrt{x}\sin\frac{1}{x}[/tex]

Homework Equations


I don't think you can use the squeeze theorem here...

The Attempt at a Solution



So I am just studying for an exam that I have tomorrow and I am going through problems that weren't assigned on our homework set, (just in case he wants to slip something in there).

I was looking at the solution to the fore-mentioned limit equation and it references the expansion of sinx. Is this necessary? I've used substitution before in problems like lim as x approaches infinity of xsin(1\x) setting 1\x as y while t approaches zero. Can that sort of thing be done here?THANKS FOR ANY HELP!
 
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To make things clearer:
let [tex]t = \frac{1}{x}[/tex]
an now the limit is
[tex]\mathop {\lim }\limits_{t \to 0} \frac{{\sin t}}{{\sqrt t }} = \mathop {\lim (}\limits_{t \to 0} \frac{{\sin t}}{t} \times \sqrt t )[/tex].
Now you shall see how to do it.
 
Thank you!
 

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