May 17, 2006 #1 Roshdy Member level 3 Joined Nov 23, 2005 Messages 57 Helped 2 Reputation 4 Reaction score 0 Trophy points 1,286 Location Egypt Activity points 1,738 solve this formula Dear all I need the result of this formula ∑(p-i)cos(iθ) , p is a constant, i is the index run from 1 to (p-1)
solve this formula Dear all I need the result of this formula ∑(p-i)cos(iθ) , p is a constant, i is the index run from 1 to (p-1)
May 17, 2006 #2 L LouisSheffield Member level 5 Joined Feb 19, 2006 Messages 82 Helped 10 Reputation 20 Reaction score 0 Trophy points 1,286 Activity points 2,164 solve this formula By MathCAD's equation solver (with rearrangement) ... ( (1-cos(pΘ))-p(1-cos(Θ)) ) / ( 2(1-cos(Θ)) ) I'll try to verify this later, but my guess is that it's correct Added after 4 hours 47 minutes: That solution (numerically) holds well for Theta > 0, but has severe problems as Theta-->0. I'm am out of town - I welcome another's help. If nothing else, I will put actual analytical time into this when I can. (sadly, it just can't be today)
solve this formula By MathCAD's equation solver (with rearrangement) ... ( (1-cos(pΘ))-p(1-cos(Θ)) ) / ( 2(1-cos(Θ)) ) I'll try to verify this later, but my guess is that it's correct Added after 4 hours 47 minutes: That solution (numerically) holds well for Theta > 0, but has severe problems as Theta-->0. I'm am out of town - I welcome another's help. If nothing else, I will put actual analytical time into this when I can. (sadly, it just can't be today)
May 18, 2006 #3 L LouisSheffield Member level 5 Joined Feb 19, 2006 Messages 82 Helped 10 Reputation 20 Reaction score 0 Trophy points 1,286 Activity points 2,164 solve this formula I was wrong - the solution is correct - the "discontinuity" I noticed is only when theta=0, which is undefined in the solution I provided. L'Hopital shows this singular point as (p^2 - p) / 2, which is the same as that of the summation. My worries were unfounded, ( (1-cos(pΘ))-p(1-cos(Θ)) ) / ( 2(1-cos(Θ)) ) is the answer.
solve this formula I was wrong - the solution is correct - the "discontinuity" I noticed is only when theta=0, which is undefined in the solution I provided. L'Hopital shows this singular point as (p^2 - p) / 2, which is the same as that of the summation. My worries were unfounded, ( (1-cos(pΘ))-p(1-cos(Θ)) ) / ( 2(1-cos(Θ)) ) is the answer.