GR9768 Question 8

Forum for the GRE subject test in mathematics.
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kthompson
Posts: 2
Joined: Wed Sep 16, 2009 7:43 pm

GR9768 Question 8

Post by kthompson » Wed Sep 16, 2009 7:51 pm

Well, it's been a long day and I'm blanking on how to start problem 8.
It asks one to integrate the following:
x/(1+x^2), bounded by [0,1].

I remember this being a tricky problem, where integration by parts can get ugly. Help?

mk
Posts: 13
Joined: Fri May 22, 2009 1:14 am

Re: GR9768 Question 8

Post by mk » Wed Sep 16, 2009 9:40 pm

Isn't it just a simple substitution? Let u = 1+x^2, du = 2xdx will cancel the top and multiply by a constant. Then you're just integrating 1/u.

kthompson
Posts: 2
Joined: Wed Sep 16, 2009 7:43 pm

Re: GR9768 Question 8

Post by kthompson » Thu Sep 17, 2009 3:06 pm

Ha. I woke up this morning and looked over the problem... it took me about 5 minutes to figure it out! Oh what wonders a little sleep can do. Thanks for the response.

Jefferythewind
Posts: 5
Joined: Sun Sep 13, 2009 2:00 pm

Re: GR9768 Question 8

Post by Jefferythewind » Fri Sep 18, 2009 3:53 am

beautiful



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