# Integrating exponential functions

1. Feb 18, 2010

### Pingunoot

How would you integrate something like xe(x^2) by using a substitution like u=x^2

2. Feb 18, 2010

### CompuChip

What is du?

3. Feb 18, 2010

### Pingunoot

2x, but my problem is how will this help when you still have e raised to the power u

4. Feb 18, 2010

### elibj123

Do you know what's

$$\int e^{u}du$$

?

5. Feb 18, 2010

### Pingunoot

no this is what im stuck on

6. Feb 18, 2010

### elibj123

Well, you know that integration is some sort of anti-derivative, and you know that a function of which derivative is e^x, is e^x it self. So it's safe to say that:

$$\int e^{u}du=e^{u}+C$$

7. Feb 18, 2010

### Pingunoot

Thanks for your help, that cleared things up.

8. Feb 18, 2010

### Anonymous217

just to clarify, du is 2x(dx), not just not 2x. i'm sure you already knew that though.