How do I even go about solving this? I get as far as u = x^4+1 and du = 4x^3
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what if you put ?
Alright so I changed it so that it's and .
Eventually I get to and couldn't proceed.
The du becomes x^2 but I don't know what to do with the second one. It could become arctan u, but the fact that it's and not just prevents that from happening.
no, actually your substitution won't work since you need to express in terms of your substitution and that is nasty.
try my sub. and see what happens.
Originally Posted by Krizalid what if you put ? What's t? du or u?
it's any variable, that makes no difference.
Alright so ,
Do I separate? Does it become ?
In which case the answer should be 4 * x^2 * arctan x^2 + C, right?
no, it's not the answer, but it's close.
check your solution.
I'm pretty sure I messed up on the du in the solution. But I don't understand... isn't that what it's supposed to be? du is 2x and when it's integrated it should become x^2.
Originally Posted by Archduke01 I'm pretty sure I messed up on the du in the solution. But I don't understand... isn't that what it's supposed to be? du is 2x and when it's integrated it should become x^2. Once you get the integral to use the same trigonometric substitution I explained to you in another thread.
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