/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 14 Evaluate the following limits us... [FREE SOLUTION] | 91Ó°ÊÓ

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Evaluate the following limits using Taylor series. $$\lim _{x \rightarrow \infty} x \sin \frac{1}{x}$$

Short Answer

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Question: Evaluate the limit of x * sin(1/x) as x approaches infinity using the Taylor series. Answer: 1

Step by step solution

01

Taylor series of sin(1/x)

The Taylor series for the sine function, sin(u), centered at 0 is given by: $$\sin(u) = \sum_{n=0}^{\infty}\frac{(-1)^n}{(2n+1)!}u^{2n+1}$$ We want the Taylor series of sin(1/x) around x=0, so we replace u with 1/x: $$\sin \left(\frac{1}{x}\right) =\sum_{n=0}^{\infty}\frac{(-1)^n}{(2n+1)!}\left(\frac{1}{x}\right)^{2n+1}$$
02

Multiply by x

Now we need to multiply the above series by x: $$x\sin \left(\frac{1}{x}\right) = x \left(\sum_{n=0}^{\infty}\frac{(-1)^n}{(2n+1)!}\left(\frac{1}{x}\right)^{2n+1}\right)$$ Simplifying this expression, we get: $$x\sin \left(\frac{1}{x}\right) =\sum_{n=0}^{\infty}\frac{(-1)^n}{(2n+1)!}\frac{1}{x^{2n}}$$
03

Find the limit as x approaches infinity

We want to find the limit as x approaches infinity for the expression above: $$\lim_{x \rightarrow \infty} \sum_{n=0}^{\infty}\frac{(-1)^n}{(2n+1)!}\frac{1}{x^{2n}}$$ Notice that the first term of the series is when n=0: $$\frac{(-1)^0}{(2(0)+1)!}\frac{1}{x^{2(0)}} = \frac{1}{1!} = 1$$ As x approaches infinity, the remaining terms of the series with n≥1 will approach 0 because the denominators will become larger and larger. Hence, only the first term will have a significant value. $$\lim_{x \rightarrow \infty} x\sin \left(\frac{1}{x}\right) = 1$$
04

Conclusion

Therefore, using the Taylor series, we can find that: $$\lim _{x \rightarrow \infty} x \sin \frac{1}{x} = 1$$

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Most popular questions from this chapter

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