Integration of Inverse Tangent Function

Lanza52
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[SOLVED] Integration of Inverse Tangent Function

\int \frac{e^{x}}{4+9e^{2x}}dx

Saw the problem, looked at it for a bit. Noticed that it is a inverse Tangent function. Played with some integration by parts and substitution and couldn't figure it out. Can anybody toss me a starting point on this problem?

Thanks
 
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Think of 9e^(2x) as (3e^x)^2, that should get you started.
 
you're aim should be to put your integral in this form \int\frac{1}{a^{2}+x^{2}}dx so algebraically manipulate it as hotcommodity suggested.
 
Ahh...thank you guys =P

For some reason I wasn't letting myself put the 9e^2x as (3e^x)^2. Basic order of operations tricks me 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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