Integrating x^3/(1+x^2) from 0 to 1.48766439

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Homework Statement


I have to take an integral of x^3/(1+x^2) from zero to 1.48766439...(I have the number).


Homework Equations


None really.


The Attempt at a Solution


Well, I tried and tried, and I could not find a single way to separate the top from the bottom. Also, I tried u substitution of both x^3 and 1+x^2 but it never seemed to work out. I'm not sure if this would be good for integration of parts, since I believe that one must be able to be integrated multiple times, such as e^x, so any nudge in the right direction would help. I have the correct answer, I just would like to be able to know how to get to it. Thank you for your time.

-Swerting
 
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Try writing it as x^2*x/(1+x^2). Now substitute u=1+x^2. Replace the x^2 in the numerator by u-1. Do you see it now?
 
Ah yes! I completely forgot about that! Thank you very much, I do believe I have it now!
 
There are two things I don't understand about this problem. First, when finding the nth root of a number, there should in theory be n solutions. However, the formula produces n+1 roots. Here is how. The first root is simply ##\left(r\right)^{\left(\frac{1}{n}\right)}##. Then you multiply this first root by n additional expressions given by the formula, as you go through k=0,1,...n-1. So you end up with n+1 roots, which cannot be correct. Let me illustrate what I mean. For this...
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