Integrals

Hi /sci/

I'm having orals for a french computer engineering school (i'm french). Amongst those orals, there is a maths oral. The thing is, we didn't study integrals in class yet. And the book is f*** stupid. So could anybody clearly explain to me what integrals are, how they work, etc.

Thanks a lot ;)

>>8
Damn, and it looked so harmless at first. No way to even solve it partly, through substituion or otherwise? Numerically solved it looks like it could be an arctan of sorts. Gonna seek the wisdom of Bronstein tommorow, maybe he will help.