Calc integration help

[Rahminator]

I need to solve an indefinite integral x / (1 + x^4) for homework but I keep getting 1/2 arctan(x^2) as my answer even though I know the correct answer is -1/2 arctan (1/x^2). I have to use substitution, and the way I'm approaching this problem is by setting u = x^2. This way, I'm cancelling out the x in the numerator and setting x^4 in the denominator to u^2. I dunno what I'm doing wrong, anyone care to give me a hand? Thanks a lot in advance.

 

[Kyteland]

I agree with your answer. Why do you know that it is wrong?

 

[dighn]

your answer is the right one. its derivative is the original expression.

 

[DanFungus]

yeah, (1/2)*arctan(x^2) is the right answer

 

[silverpig]

I am god


edit: you don't NEED a password. that's only for integrals if you want the step by step. derivatives and others give you a full out step by step way to do it without the password.

honestly though, if i was back in calc I, i'd front the cash for a password.

 

[silverpig]

webmathematica says you are correct btw

 

[Rahminator]

I used this to check my answer and that's what threw me off. Thanks guys.