How Accurate Is the Maclaurin Series for \( f(x) = x^2e^{-2x^2} \)?

AI Thread Summary
The discussion focuses on finding the Maclaurin series and the 100th degree Maclaurin polynomial for the function \( f(x) = x^2 e^{-2x^2} \). The initial series presented for part (a) is correct, expressed as the infinite sum. For part (b), clarification is provided that the 100th degree polynomial should only include terms up to \( x^{100} \), leading to the correct expression being the sum from \( n=0 \) to \( n=49 \). The original post contained an error regarding the degree of the polynomial, which has since been corrected. The thread emphasizes the importance of accurately determining the degree of the polynomial in relation to the series expansion.
RadiationX
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I need some peer review of this quesion. Let f(x)=x^2e^{-2x^2}

(a) find the maclaurin series of f

(b) find the 100th degree maclaurin polynomial of f.


for part a i have:\sum_{n=0}^{\infty}\frac{(-2)^nx^{2n+2}}{n!}

and for b:\sum_{n=0}^{99}\frac{(-2)^nx^{2n+2}}{n!}
 
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does anyone have a review for me?
 
It looks good. I'm not sure what you mean by the 100th degree MacLaurin polynomial, but if you mean the expansion up to the 100th power of x you have too many terms, since it goes up to the 2(99)+2=200th power of x.
 
Are u sure...?

What is f^{\mbox{iv}}(x)...?And then,of course,f^{\mbox{iv}}(x)...?

Daniel.
 
RadiationX said:
I need some peer review of this quesion. Let f(x)=x^2e^{-2x^2}

(a) find the maclaurin series of f

(b) find the 100th degree maclaurin polynomial of f.


for part a i have:\sum_{n=0}^{\infty}\frac{(-2)^nx^{2n+2}}{n!}

and for b:\sum_{n=0}^{99}\frac{(-2)^nx^{2n+2}}{n!}


This is the 100th degree maclaurin polynomial let 100=2n+2 so that n=49 now we have this:\sum_{n=0}^{49}\frac{(-2)^nx^{2n+2}}{n!}

my oginal post of part (b) was incorrect. now this is correct
 
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