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EDIT/UPDATE: I DO NOT NEED A SOLUTION. SEE SOS440 COMMENT FOR A FULL DETAILED SOLUTION.

Hi I am trying to integrate $$ \int_0^{\phi_0} \arctan \sqrt{\frac{\cos \phi+1}{\alpha \cos \phi +\beta}}d\phi, $$ where $\alpha > |\beta|$ and min$_{0\leq \phi \leq \phi_0}(\alpha\cos \phi +\beta)\geq 0$.

I think this class of integrals is from the early 2000's mathematics journals, however I may be mistaken. Any literature on this would be very helpful as well.

Some ideas I had were trying to use trig identities to first re-write the square root expression by using $$ \frac{1}{2}(1+\cos \phi)=\cos^2\frac{\phi}{2},\quad \alpha\cos\phi+\beta=\alpha+\beta-2\alpha \sin^2\frac{\phi}{2}, $$ however I am not sure where to go from here. Thank you for reading.

Jeff Faraci
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    I have been working with exactly that version of Coxeter's integral and found that it is directly related to the family of Ahmed's integral. – Sangchul Lee Apr 06 '14 at 21:35
  • @sos440 Do you have literature on this or a solution? I am not familiar with Coxeter integrals surprisingly. How long they have been around?? Thank you very much for this information – Jeff Faraci Apr 06 '14 at 22:06
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    I think this document would be helpful. You cac refer to the final section. – Sangchul Lee Apr 06 '14 at 22:19
  • @sos440 THIS IS EXCELLENT I WISH I COULD UPVOTE THIS AS AN ANSWER. feel free to post this as an answer, this is a keeper in my integration collection. thank you very much for this +10.

    do you use LaTex? How do you write your integral signs? They are not as slanted to the right as the one's on this site, instead they are straight up. http://en.wikipedia.org/wiki/File:Integral_Uprightness.svg.

    – Jeff Faraci Apr 06 '14 at 22:23
  • @sos440 Your document is very impressive. This is the best I have seen on MathStackExchange. Thanks. – Jeff Faraci Apr 06 '14 at 22:27
  • @sos440 Could you please convert your comment to an answer? Ping me back when you're done. – Aditya Hase Dec 16 '14 at 13:22
  • @Iuʇǝƃɹɐʇoɹ, Sorry, I forgot to respond to your comment. In fact I am making some other trials for calculating various Ahmed integrals and Coxeter integrals. So I decided not to make a formal answer before it is done or I give up. – Sangchul Lee Dec 28 '14 at 04:29

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