## Thread of Luck and Happiness

Forum for the GRE subject test in mathematics.
EugeneKudashev
Posts: 27
Joined: Tue Apr 06, 2010 8:22 am

### Thread of Luck and Happiness

for everyone sitting the exam this saturday - evaluate $$\int\limits_{0}^{1}\ln^5\frac1x\,dx$$ and be sure to score 90% or higher

wish you luck guys with the test!

origin415
Posts: 61
Joined: Fri Oct 23, 2009 11:42 pm

### Re: Thread of Luck and Happiness

Best of luck everyone!

obpizdon
Posts: 4
Joined: Wed Apr 07, 2010 11:52 am

### Re: Thread of Luck and Happiness

It's very easy.

First change of variable is 1/x = t, then ln(t) = z, so we obtain the standard integral x^n*exp(-ax) from 0 to oo, as you should know it is equal to n!/a^(n+1). This fact can be derived from integration by parts hm.. n times. Thereby, the answer is 5! = 120.

Good luck!

З.Ы. Integrals aren't my weakness. I'm worried about topology and abstract algebra. Sometimes that's a hard nut to crack.