How do I solve the trigonometric integral of f(x)=cotx+tanx?

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Part 2, leading on from https://www.physicsforums.com/showthread.php?t=315803"

Homework Statement


Given f(x)=cotx+tanx find
\int{[f(x)]^2}dx

The Attempt at a Solution


I've attempted many different varieties of approaches to the problem. Trying to use the substitution method for sinx, cosx, tanx... and a few others... re-arranging the function, trying to get it into a more convenient form... trying to use some of the ideas given in the first thread... No luck.

Basically, it has all been a bunch of guessing and hoping something useful will appear. Plus another bunch of frustration on my part, but I won't get into the details of that xD
 
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Expand out [f(x)]^2

use cot^2x+1=cosec^2x and tan^2x+1=sec^2x
 
Thanks rockfreak :smile:

It turns out to be tanx-cotx. I also obtained \int{sec^2x+cosec^2x}dx through another longer method but it strike me at that moment that I can take the integral of each of these. (I think I'll keep my standard integral formulas close-by next time).

Thanks again.
 
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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