Services & Resources / Wolfram Forums
-----
 /
MathGroup Archive
2006
*January
*February
*March
*April
*May
*June
*July
*August
*September
*October
*November
*December
*Archive Index
*Ask about this page
*Print this page
*Give us feedback
*Sign up for the Wolfram Insider

MathGroup Archive 2006

[Date Index] [Thread Index] [Author Index]

Search the Archive

Re: Why all the if's the answer

  • To: mathgroup at smc.vnet.net
  • Subject: [mg70800] Re: [mg70783] Why all the if's the answer
  • From: Carl Woll <carlw at wolfram.com>
  • Date: Sat, 28 Oct 2006 05:21:37 -0400 (EDT)
  • References: <200610270428.AAA24487@smc.vnet.net>

aaronfude at gmail.com wrote:

>Suppose I start with :
>
>f = -Log[y*(1 + Cos[alpha])] + Log[(b*c - b*y + c*y*Cos[alpha] +
>Sqrt[b^2*(c - y)^2 + c^2*y^2 + 2*b*c*(c - y)*y*Cos[alpha]])/c];
>
>which I think is relatively innocent. I then integrate over y:
>
>Assuming[y > 0 &&  c > 0 && b > 0 && alpha > 0 && alpha < Pi/2,
>Integrate[y/c*f, {y, 0, c}]]
>
>After a few hours get a humongous answer with many If's, etc. What else
>can I assume or otherwise do to get an analytical answer?
>
>Many thanks in advance!
>
>Aaron Fude
>  
>
Try

Integrate[y/c*f, {y, 0, c}, GenerateConditions -> False]

This will return an answer much more quickly, but you will have to 
figure out whether the result is valid for the parameter ranges you are 
interested in.

Carl Woll
Wolfram Research


  • Prev by Date: Re: package problem
  • Next by Date: Re: kernel error: invalid machine instruction
  • Previous by thread: Re: Why all the if's the answer
  • Next by thread: Re: Why all the if's the answer