How can I effectively use substitution to evaluate this integral?

htoor9
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Homework Statement



Evaluate the integral.

Int((x+5)(x-5)^(1/3)dx

Homework Equations


The Attempt at a Solution



I've attempted the problem but subsitution doesn't seem to do anything, as du = dx if u = x-5, which doesn't cancel anything.
 
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That's exactly the substitution you want to go with. If u=x-5 then x=u+5, which you can use in the other factor in the integrand.
 
Tom Mattson said:
That's exactly the substitution you want to go with. If u=x-5 then x=u+5, which you can use in the other factor in the integrand.

So then what? I have integral of (u+10)(u)^(1/3) du.
 
htoor9 said:
So then what? I have integral of (u+10)(u)^(1/3) du.

Expand the u^(1/3) into both terms. It should be easy to integrate then.
 
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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