# Homework Help: Using Integration by Parts

1. Feb 25, 2007

### LiveToDream

1. The problem statement, all variables and given/known data
indefinite integral dx/((e^x)(sqrt(1-e(-2x))))
using integration by parts evaluate the integral.

2. Relevant equations

integral u*dv = u*v- integral v*du

3. The attempt at a solution

To be completely and entirely honest i am not even sure where to start with this problem. I have finished other integration by parts homework questions in this assignment but this one i can't find something to choose for u and dv that will work out correctly.:grumpy: I have been at this problem alone from almost 2 hours. Any help would be greatly appreciated.

2. Feb 25, 2007

### imranq

Are you sure it wasn't

$$\sqrt {1-e^{-2x}}$$

instead of $$\sqrt {1-e(-2x)}$$, since that is a very strange way of writing it.

If so, just remember that $$\frac {1}{e^{x}} = e^{-x} = \sqrt {e^{-2x}}$$ and set $$u = e^{-2x}$$

Last edited: Feb 25, 2007
3. Feb 25, 2007

### LiveToDream

It was supposed to be
1/ $$\sqrt {1-e^{-2x}}$$

**How did you get that equation to show up that way? I just copy and pasted what you had to make it work this time and was curious how i would go about doing that.

Last edited: Feb 25, 2007
4. Feb 25, 2007

### imranq

There is a \frac command in LaTex. To use it just type \frac {numerator}{denominator}

So your problem would show up as:

$$\int {\frac{dx}{e^{x}\sqrt{1-e^{-2x}}}$$

**Also check out this guide to LaTex typesetting
https://www.physicsforums.com/misc/howtolatex.pdf

Last edited: Feb 25, 2007
5. Feb 25, 2007

### LiveToDream

Thank You for your help. It is really appreciated.

6. Feb 26, 2007

### HallsofIvy

If nothing else there is a "^" key on your computer that can be used to indicate exponents.