(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

Let [itex]f(x) = \arctan(\frac{1+x}{1-x})[/itex]

Find [itex]f^{2005}[/itex](0)

2. Relevant equations

I'm guessing this has to do with maclaurin's?

3. The attempt at a solution

...

[itex]

f(x) = \pi /4 + \sum^∞_{n = 0} \frac{(-1)^n}{2n+1}x^{2n+1}

[/itex]

[itex]\sum^∞_{n = 0}\frac{f^n(0)x^n}{n!} = \pi /4 + \sum^∞_{n = 0} \frac{(-1)^n}{2n+1}x^{2n+1}[/itex]

So anyone knows how I go about from here? The answer is 2004!(factorial)

How do you compare two infinite series can you cancel them out?

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# Homework Help: Using Maclaurin series to find 2005-order derivative

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