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|    sci.math.symbolic    |    Symbolic algebra discussion    |    10,432 messages    |
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|    Message 9,237 of 10,432    |
|    clicliclic@freenet.de to oldk1331@gmail.com    |
|    Re: alarum: Risch integrator fails to di    |
|    15 Jan 17 18:32:57    |
      oldk1331@gmail.com schrieb:       >       > [...] I think there is no symbolic result for       > "integrate((1 + x)/((1 + x + x^2)*(a + b*x^3)^(1/3)), x)".       > When a,b are integers, FriCAS can give symbolic results.              Wow - we could all become world-famous if this proves to be the first       parametrized algebraic integrand with this property! Alas, my Derive       oracle says:               goursat5a((x + 1)/(x^2 + x + 1), x, a, 0, 0, b)               [false, false, false, true, true]              which means integrable :(. Might something else perhaps be amiss with       the current "demonstration-only" code of FriCAS?              >       > [...] For this example, I have post a small patch to fricas-devel.       > After my patch, FriCAS gives continuous result, same as SymPy.              Thanks, I myself obtain (up to some piecewise constant):               ATAN(SQRT(11)*(10*x + 3)/(80*x^2 + 10*x - 9)) =        - ATAN(SQRT(11)*(800*x^3 - 40*x^2 + 30*x + 57)/66)        - ATAN(SQRT(11)*(40*x - 7)/55)              Martin.              --- SoupGate-Win32 v1.05        * Origin: you cannot sedate... all the things you hate (1:229/2)    |
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