Evaluate the definite integral.

neosonata
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Homework Statement



Integrate from 0 to 1

x47e-x48

Homework Equations





The Attempt at a Solution



u = -x48

du = -48x47dx

dx = du / -48x47


∫eu * du/-48

-\frac{1}{48} ∫ eu du

-\frac{1}{48} eu


-\frac{1}{48} e1 - ( -\frac{1}{48} e0)


-\frac{e}{48} + \frac{1}{48}


\frac{1-e}{48}



What did I do wrong? Webassign marked this as incorrect but I redid it and got same answer.
 
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When x=1, u=-1.
 
neosonata said:
-\frac{1}{48} e-1 - ( -\frac{1}{48} e0)

Here's your problem. e^(-(1)^(48)) = e^(-1), not e^1.
 
I see what I did wrong now, thank you.
 
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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