# Integral of e^(6x)/(e^(6x)+6)

1. Nov 18, 2009

### Zvaigzdute

Hi I have to find the indefinete integral of

e^(6x)/(e^(6x)+6)*dx

And I get

1/6*(ln(e^6x+6)) +C

What am I doing wrong?

Thank you

2. Nov 18, 2009

### arildno

Why do you think it has gone awry?

3. Nov 18, 2009

### Zvaigzdute

All of my calculus homework is submitted online to Web assign, and the website says that this is wrong. I cannot see where I may have made a mistake, and I was wondering if somebody could point it out, and show me how to get to the right answer

4. Nov 18, 2009

### df508462

Perhaps the online answer is looking for an absolute value of the quantity (e^6x + 6) in the argument of the ln in your answer?

You are justified in removing the absolute value, since
(e^6x + 6) > 0 for all real x.

5. Nov 18, 2009

### arildno

1. Is the conventional Web Assign code for the undetermined constant "C"?

2. Sometimes, "log" is used as denoting "ln", since Briggsian logarithms are beyond moribund.

6. Nov 18, 2009

### g_edgar

(1) Do you have to write * for multiply on that web interface? If so, your answer does not qualify.

(2) If you write e^6x it probably means (e^6)*x, and that is certainly wrong.