- #1
dlthompson81
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Homework Statement
\begin{equation} \int \frac{e^{x}+1}{e^{x}}\end{equation}
Homework Equations
The Attempt at a Solution
This problem comes out of the substitution section of my book, and the answer in the back of the book is [itex]x-e^{x}+C[/itex]
I started by changing the form to this:
\begin{equation}\int \frac{1}{e^{x}}e^{x}\end{equation}
I set u = [itex]e^{x}[/itex] and du is the same.
That left me with:
\begin{equation}\int \frac{1}{u} du\end{equation}
Integrating [itex]\frac{1}{u}[/itex] gives ln|u|
So plugging u back in gives [itex]ln|e^{x}|[/itex]
I plugged some test numbers into my answer and the book answer and they come out pretty close, so I thought both of them may be right, but I still can't figure out how to get [itex]x-e^{-x}[/itex].
Any ideas?