Question

evaluate the integral

Answer 1

\[\int\limits \frac{ x^2 }{ (1-x^4)\sqrt{1+x^4} } dx\]

Answer 2

@agent0smith ??

Answer 3

Do you have any guesses? What have you tried?

Answer 4

not much really ..substituted x=sint but couldnt go much far...

Answer 5

Idk. Good luck. When wolfram can't do it, I am not willing to try. http://www.wolframalpha.com/input/?i=%5Cint%5Climits+%5Cfrac%7B+x%5E2+%7D%7B+%281-x%5E4%29%5Csqrt%7B1%2Bx%5E4%7D+%7D+dx

Answer 6

I mean, can't do it without introducing crap I've never heard of.

Answer 7

I was thinking multiplying by the conjugate would solve it, but yeah now I can't seem to get anything of any niceness to come out of it haha.

Answer 8

oh a new function

Answer 9

ahh ...ohhk ..crap ..?

Answer 10

http://mathworld.wolfram.com/AppellHypergeometricFunction.html

There you go. That'll learn you good.

Answer 11

Where'd you get this integral from?

Answer 12

I thought maybe he meant it was \[\large \int\limits\limits \frac{ x^2 }{ (1+x^4)\sqrt{1+x^4} } dx\] but that's even worse!!! http://www.wolframalpha.com/input/?i=%5Cint%5Climits+%5Cfrac%7B+x%5E2+%7D%7B+%281%2Bx%5E4%29%5Csqrt%7B1%2Bx%5E4%7D+%7D+dx

elliptic integral? Now they're just making things up.

Answer 13

one of the questions in my study material ..
answer is given as ..\[\frac{ 3 }{ 2 }x ^{2/3} + 6arc \tan{\sqrt[6]{x}} +c\]

Answer 14

then most probably there must be some incorrectness in the problem..

Answer 15

^the derivative of that looks NOTHING like the integral above. Not a good sign for this problem.

Answer 16

yes true ..haha weird problems

Answer 17

I mean the exponent of 2/3 just magically disappeared to become a nice neat 2 or 4.

Answer 18

hahah ..1 yeahh..how i wonder too ..:)

Answer 19

Tonight's just a nightmare for integrals.

Answer 20

how did you came up with this equation
???

Answer 21

oh ..is that so ..1 sounds like ..u ll try the whole night over this problem ..?

Answer 22

No one is trying the whole night over this problem. I wonder if there's anyone here familar with the Appell Hypergeometric Function.

Answer 23

i am a 10th grade student...!

Answer 24

This is where wolfram alpha can save you time though. You can use it to check if you're given a problem which is actually possible to solve, or there's some kinda mistake. If W.A. shows a reasonable solution, then go ahead and try to work it out.

Answer 25

thank you ..yes u are right ..!