MHB Integral by Parts: Solving 2 Integrals Involving Arctg(x) & Sqrt(1-x^2)

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The discussion revolves around solving the integral of arctg(x)/sqrt(1-x^2). One suggested method involves using a substitution where u = arctg(x) and du = 1/(1+x^2), but there is skepticism about finding a straightforward antiderivative. Another approach proposed is using the MacLaurin series expansion to integrate term by term, although this method is not suitable for students who haven't learned series. Participants express frustration over being asked to solve complex integrals without the necessary background knowledge. The conversation highlights the challenges of tackling advanced calculus problems with limited instructional support.
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integral of arctg(x)/sqrt(1-x^2)

maybe u = arctg x du = 1 /1+x^2
but x = tg u
maybe this is the way isn't it?
 
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Wolfram couldn't find an antiderivative so I doubt there is one...
 
leprofece said:
integral of arctg(x)/sqrt(1-x^2)

maybe u = arctg x du = 1 /1+x^2
but x = tg u
maybe this is the way isn't it?

A possible approach is to use the MacLaurin expansion...

$\displaystyle \frac{\tan^{-1} x}{\sqrt{1-x^{2}}} = x + \frac{1}{6}\ x^{3} + \frac{49}{120}\ x^{5} + \frac{81}{560}\ x^{7} + \mathcal{O}\ (x^{9})\ (1)$

... and to integrate term by term...

Kind regards

$\chi$ $\sigma$
 
chisigma said:
A possible approach is to use the MacLaurin expansion...

$\displaystyle \frac{\tan^{-1} x}{\sqrt{1-x^{2}}} = x + \frac{1}{6}\ x^{3} + \frac{49}{120}\ x^{5} + \frac{81}{560}\ x^{7} + \mathcal{O}\ (x^{9})\ (1)$

... and to integrate term by term...

Kind regards $\chi$ $\sigma$

Thank for your answer but you must solve it by normal or traditional methods students have not studied series yet
Could anybody do that way??
 
leprofece said:
Thank for your answer but you must solve it by normal or traditional methods students have not studied series yet
Could anybody do that way??

Hey! :D

As with your other recent thread - for $$\int \sqrt{x}e^x\, dx$$ - it sounds like your teacher is asking you to do stuff without him or her teaching you the things necessary to solve the problem... (Headbang)
 
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