# Simple single variable integral calc

1. Feb 25, 2008

### chromecarz00

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

e^x dx
1+e^2x

2. Relevant equations

3. The attempt at a solution

Its the e^x and the e^2x thats tripping me up, i know that e^x is just itself but what is the rule behind e^2x?

2. Feb 25, 2008

### PowerIso

u = e^x
du= e^xdx

u/(1+u^2)du

Does that look like something (think arc(something))

3. Feb 25, 2008

### rocomath

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

$$u=e^x$$
$$du=e^xdx$$

PowerIso meant ...

$$\int\frac{du}{1+u^2}$$