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dimmechan (1125) 313 Articles, 812 Replies, 1125 Points
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Since 5/20/2012 2:41:57 AM, dimmechan has written 313 articles and participated in 812 conversations.
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dimmechan

dimmechan's articles:
 Items(313) /32 Next >> Last >| a bug in Integrate (2nd message) 0 53 (10/22/2011 10:13:25 AM) comp.soft-sys.math.mathematicaint = 1/((x^2 + x + 1)*Sqrt[x^2 - x + 1]); As I told in the previous message Mathematica gives wrong result for the following integral Integrate[int, {x, -1, 0}] the problem is (I guess from what I fi...dimitris a bug in Integrate #2 0 51 (10/22/2011 10:11:21 AM) comp.soft-sys.math.mathematicaThe following has a connection with the recent post of mine called Simplification. http://groups.google.com/group/comp.soft-sys.math.mathematica/browse_thread/thread/b6e8fc7f70a0f20f# Let int = 1/((x^...dimitris simplification #6 1 67 (10/19/2011 9:40:01 AM) comp.soft-sys.math.mathematicaHello to all. I would appreciate your suggestions about simplifying further the following lengthy expression. ArcTan[(3*(Sqrt[3] + I*x - I*x^2)*(1 - x + x^2))/(-3 + I*Sqrt[3] - 3*x - 3*I*Sqrt[3]*x + 3*x...dimitris Find two numbers a,b such us: a+b=5432 & LCM[a,b]=223020 0 50 (10/16/2011 8:46:36 PM) comp.soft-sys.math.mathematicaThis is taken from the recent book (2010): " Mathematica: A Problem- Centered Approach" by R. Hazrat. "The sum of two positive integers is 5432 and their least common multiple is 223020. Find the numbers....dimitris list equation 5 55 (10/6/2011 8:38:44 AM) comp.soft-sys.math.mathematicaHello to all. Let lst = Tuples[Range[100], 2]; In the previous list appear elements such us {x,y} and {y,x}. (e.g. {3,4} and {4,3}). I want to create a new list with {y,x} dropped (that is, in the ne...dimitris simplification #5 11 53 (10/4/2011 5:40:51 AM) comp.soft-sys.math.mathematicaHello. Let o1 = 1 + Sqrt[15 + 2*Sqrt[35] + 2*Sqrt[6*(6 + Sqrt[35])]]; o2 = 1 + Sqrt[3] + Sqrt[5] + Sqrt[7]; o1 is equal to o2. o1 == o2 // FullSimplify True The question is how to make Mathemat...dimitris count zeros in a number 13 70 (10/2/2011 6:40:04 AM) comp.soft-sys.math.mathematicaHello. Consider e.g. the number 24^24*55^55. This number ends with exactly 55 zeros as the following demonstrate In[201]:= Mod[24^24*55^55, 10^55] Mod[24^24*55^55, 10^56] Out[201]= 0 Out[202]= 20000...dimitris HoldForm and Sum 3 54 (10/1/2011 7:08:15 AM) comp.soft-sys.math.mathematicaHell to all. A (well-known) nice example of the use of HoldForm is: Sum[(HoldForm[#1] & )[i], {i, 1, 10}] (*output omited*) I want to do the same with 1/i Sum[(HoldForm[#1] & )[1/i], {i, 1, 10}] ...dimitris unable to save notebook 0 107 (7/21/2011 9:54:11 AM) comp.soft-sys.math.mathematicaHello to all. When my student tries to save a document (e.g. hh its name) the following message appears... "Mathematica could not find enough disk space to save the file C:\Users \=D7\[Rho]=DE\[Sigma]\[Ta...dimitris Boundary Value Problem (a correction) 0 49 (8/2/2009 9:55:22 AM) comp.soft-sys.math.mathematicaMay be is the hot weather in Greece, but the fact is that I forgot to write that the boundary conditions > bc1 = (b^2 - 2)*D[f[x, y], {x, 2}] - 2*D[g[x, y], {x, 1}, {y, 1}] == (- > P)*DiracDelta[x]; > bc2...dimitris

dimmechan's replies:
 Items(589) /59 Next >> Last >| Solving a simple equation 4 65 (10/4/2011 5:39:49 AM) comp.soft-sys.math.mathematicaHi there, I wonder why the following equation cannot be solved: \[Kappa] = 1.4 \[CapitalTheta] = 10; NSolve[Tan[\[Theta] degree] == 2*Cot[\[Beta] degree]*(ma1^2*Sin[\[Beta] degree]^2 - 1)/( ma1^2*(\...eizdealer (1) Only real data 3 70 (10/15/2011 10:05:59 AM) comp.soft-sys.math.mathematicaHello, I have a problem to exclude complex solutions. I tried data1={2,3/4,1.3,=E4} {2,3/4,1.3,=E4} Cases[data1, Except[_Complex]] {2,3/4,1.3} and got, what I expected.... How to create this kind of list 5 63 (10/15/2011 10:08:32 AM) comp.soft-sys.math.mathematicaHello there, I am thinking about creating such a list. I have 2 lists with the same number of elements. The idea is to create one list which was taken from these previous two ones in the following way: Tak...szymon.roziewski (16) Limit of nested function 1 85 (10/16/2011 8:47:07 PM) comp.soft-sys.math.mathematicaHow can I to calculate the limit of a nested function . Mathematica 6 yields an error message "... Non negative machine size integer ...". For example, let f[x,n]=Nest[Sqrt[# Sqrt[#]]&,x,n] For x=3,...mibelair (8) simplification #6 1 67 (10/19/2011 9:40:01 AM) comp.soft-sys.math.mathematicaHello to all. I would appreciate your suggestions about simplifying further the following lengthy expression. ArcTan[(3*(Sqrt[3] + I*x - I*x^2)*(1 - x + x^2))/(-3 + I*Sqrt[3] - 3*x - 3*I*Sqrt[3]*x + 3*x...dimmechan (1125) Simplifying radicals #2 7 51 (10/20/2011 11:49:28 AM) comp.soft-sys.math.mathematicaHi, I'm working with some introductory topics in radicals. I know that Mathematica assumes things about the domain used in problems, so the principal cube root of a negative number will be complex... or ...tidetabletom (11) can not understand the symbol or the equation for an integration result 1 54 (10/21/2011 10:30:17 AM) comp.soft-sys.math.mathematicaHi, I am trying to integrate a equation, 1/72 (8 Sqrt[3] r^3 - Sqrt[3] r^2 Sqrt[r^2 + 2 y (y - Sqrt[3] Sqrt[r^2 - y^2])] - 2 Sqrt[3] y^2 Sqrt[r^2 + 2 y (y - Sqrt[3] Sqrt[r^2 - y^2])] + 6 y ...jing.guo89 (7) count the number of sub-list in a list 3 52 (10/21/2011 11:29:12 AM) comp.soft-sys.math.mathematicaDear All, I have a list like: {{{{-0.00201671, 0.87571, 0.482832}, {-0.839678, 0.260735, -0.476401}, {-0.543081, -0.406384, 0.734789}}, {{-0.87571, -0.00201671, 0.482832}, {-0.260735, -0.83...hitphyopt (5) how do you prevent numerator expansion when using 'Together'? 1 48 (10/22/2011 10:12:24 AM) comp.soft-sys.math.mathematicaI'm using Mathematica 8. When using 'Together' on an expression the numerator is always expanded, complicating the appearance of the final result: In: Together[ (a+b)/d + ((a+b)*(e+f))/(d*g) ] ...dushanm2 (40) Full simplify problem 4 68 (10/22/2011 10:18:37 AM) comp.soft-sys.math.mathematicaHello, Could anyone explain why the following does not give zero? In[72]:= Assuming[ x == y + z, FullSimplify[ E^x - E^(y + z) ] ] Out[72]= E^x - E^(y + z) Thanks! ...ffcitatos (7)