# Homework Help: Imposible Integral?

1. Jun 26, 2012

### Sebobas

1. The problem statement, all variables and given/known data

I have to find the definite integral of: $\int\left(\sqrt[3]{1-x^{7}}-\sqrt[7]{1-x^{3}}\right)dx$ with bounds [0,1]

2. The attempt at a solution

I know that this can be done with hypergeometric functions, but I ca't use them because "we haven't seem them yet", so I have to do this with "everyday" integration tools. The only thing I was told was that I have to start with a substitution and the last part would be a cyclical integral, which tells me that I probably have to also use integration by parts in the middle.

I'm not asking for someone to give me the answer right away, I just need a starting point/mini-guide to help me get to the answer on my own, although I'm grateful with any kind of help (: Thanks!

Last edited: Jun 27, 2012
2. Jun 27, 2012

### clamtrox

Which substitutions have you tried so far?

3. Jun 27, 2012

### Sebobas

u= x7, x3, 1-x3, 1-x7

4. Jun 27, 2012

### Curious3141

Sure that's not a definite integral with bounds of [0,1]?

Because there's a neat trick to immediately and trivially evaluate it in that case. See my earlier post in this thread: https://www.physicsforums.com/showthread.php?t=571323

5. Jun 27, 2012

### Infinitum

Wow, that's a really nice trick.

6. Jun 27, 2012

### Sebobas

It is!!! Sorry, I thought I put the bounds on the integral. I'm new here so I probably didn't do it right...fixed the post (: and thanks for that trick!