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|    sci.math.symbolic    |    Symbolic algebra discussion    |    10,432 messages    |
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|    Message 9,142 of 10,432    |
|    clicliclic@freenet.de to oldk1331@gmail.com    |
|    Re: Rubi 4.9.2 do not integrate Timofeev    |
|    19 Aug 16 10:01:06    |
      oldk1331@gmail.com schrieb:       >       > On Friday, August 19, 2016 at 1:00:37 PM UTC+8, clicl...@freenet.de wrote:       > > But the result for number six does not differentiate back; it looks like       > > an attempt at approximating the antiderivative.       >       > All five differentiate back, can you check again?       >              Yes, I fell into an old trap: multi-digit numbers split over consecutive       lines are read as products when copied into Derive, this affects the       sixth result only.              The FriCAS antiderivative shows 18 jumps along the real axis. A smooth       alternative is:              -2^(1/3)/4*(LN(2*(1-x)^3+(1-x^3))-3*LN(2^(1/3)*(1-x)+(1-x^3)^(1/~       3))-2*SQRT(3)*ATAN(1/SQRT(3)*(1-2*2^(1/3)*((1-x)/(1-x^3)^(1/3)))~       ))-2^(1/3)/12*(LN(2-(1-x^3))-3*LN(2^(1/3)-(1-x^3)^(1/3))+2*SQRT(~       3)*ATAN((1+2^(2/3)*(1-x^3)^(1/3))/SQRT(3)))+2^(1/3)/12*(LN(2*x^3~       +(1-x^3))-3*LN(2^(1/3)*x+(1-x^3)^(1/3))-2*SQRT(3)*ATAN(1/SQRT(3)~       *(1-2*2^(1/3)*(x/(1-x^3)^(1/3)))))-1/6*(LN(x^3+(1-x^3))-3*LN(x+(~       1-x^3)^(1/3))-2*SQRT(3)*ATAN(1/SQRT(3)*(1-2*x/(1-x^3)^(1/3))))              Martin.              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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