evaluate integral of 1/x^2+x+1

hi everyone, I need help to solve this problem. integral 1/x2+x+1

Is it 1x2 + x + 1\displaystyle \displaystyle{\dfrac{1}{x^2} \ + \ x \ + \ 1}

or

1x2+x+1\displaystyle \displaystyle{\dfrac{1}{x^2 + x + 1}} ?

What are your thoughts?

Please share your work with us ...even if you know it is wrong

If you are stuck at the beginning tell us and we'll start with the definitions.

You need to read the rules of this forum. Please read the post titled "Read before Posting" at the following URL:

http://www.freemathhelp.com/forum/th...Before-Posting
 
Use and memorize this formula: < link to objectionable page removed >
 
Last edited by a moderator:
Trig substitution?

hi everyone, I need help to solve this problem. integral 1/x2+x+1

Assuming you mean: 1/(x^2 + x + 1), how about completing the square?
x^2 + x + 1 = x^2 + x + 1/4 + 3/4
= (x + 1/2)^2 + 3/4
Now you should be able to do something with substitutions to get:
1/(u^2 + a^2)
and you're on your way.
 
Sorry( ma fault. Actually it was (x+1)/(x^2+x+1) and I divided it into two fractions. They are (2x+1)/(x^2+x+1) and 1/(x^2+x+1). I solved first fraction, but I do not know what to do whith second fraction. I wrote something, can you check it?please. Is it right? I used as you said trig substitution .
 

Attachments

  • image.jpg
    image.jpg
    9.9 KB · Views: 6
Top