February 28th, 2008, 02:00 PM  #1 
Member Joined: Jan 2008 Posts: 34 Thanks: 0  Sine/Cosine Integral values
I don't know how to use cosine integrals or sine integrals  but I had this problem: [((p*i)/2))Ci(p/2)] + [(p/2)Si(p/2)] + [((p*i)/2)Ci(p/2)] + (p/2)Si(p/2)]= ? Where p=pi, i=the imaginary unit, Ci=Cosine integral, Si=Sine integral Can anyone provide an answer to the above value? 
February 28th, 2008, 06:11 PM  #2 
Member Joined: Feb 2008 Posts: 89 Thanks: 0 
Greetings: The equation simplifies to zero. Note that cos(pi/2) = cos(pi/2) = 0. Thus we are left with (p/2)Si(p/2) + (p/2)Si(p/2) = pi/2  pi/2 = 0. Regards, Rich B. rmath4u2@aol.com 
February 28th, 2008, 08:32 PM  #3 
Member Joined: Jan 2008 Posts: 34 Thanks: 0 
No, I don't mean cos(pi/2) or cos(pi/2)  I know what that is. What I'm trying to do is a cosineintegral/sineintegral. But I don't know how to use them or evaluate them. Can anyone elaborate on how to find the cosineintegral of (pi/2) and (pi/2) and the sineintegral of (pi/2) and (pi/2)? 
February 29th, 2008, 09:16 AM  #4 
Senior Member Joined: May 2007 Posts: 402 Thanks: 0 
Well, it's true that Si(x)=Si(x). This cancels the sinintegral. The Ci(x) for x>0 is, however, not defined. Still, Mathematica gives the value of pi^2/2.


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integral, sine or cosine, values 
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