# Math Help - differentiating exponentials

1. ## differentiating exponentials

how do you find out if e^(3x) is divergent and what to?

2. Originally Posted by Lupus
how do you find out if e^(3x) is divergent and what to?
That is not a question, please try again posting all of the question next time.

CB

3. I see no bounds and I don't know if we're talkin' about an improper integral.

4. Originally Posted by Krizalid
I see no bounds and I don't know if we're talkin' about an improper integral.

The thread title implies we are differentiating not integrating in this case!?

CB

5. Yes but, why talkin' about convergence then.

6. Originally Posted by Krizalid
Yes but, why talkin' about convergence then.
Indeed!?

CB

7. ## Question

sorry. the full question is:

Determine if the following integral is convergent or divergent and if it is convergent find its value

(it is an integral between the limits -infinity and 0) e^3x dx.

8. Originally Posted by Lupus
sorry. the full question is:

Determine if the following integral is convergent or divergent and if it is convergent find its value

(it is an integral between the limits -infinity and 0) e^3x dx.
This is asking if the following limit exists

$\lim_{a \to \infty} \int_{-a}^0 e^{3x}\; dx$

The definite integral you should be able to write down intermediatly so what do you think?

CB