integration bug?



The expressions log(x - f10) and log(f10 - x) differ by an additive 
constant. 
So both (%o3) and  (%o4) are OK.  If you are a fan of 
integrate(1/x,x)  = log(abs(x)), try this:

(%i38) integrate(1/x,x);
(%o38) log(x)
(%i39) integrate(1/x,x), logabs : true;
(%o39) log(abs(x))

Barton

maxima-admin@math.utexas.edu wrote on 10/13/2005 04:47:03 AM:

> Hi
> 
> please take a look at the following code snippet.
> The first integration result is right, but not the second one.
> 
>                                                          b + a x
> (%i2)                        INTEGRATE( - - - - - - -, x)
>                                                          d + c x
>                         a x   (a d - b c) LOG(c x + d)
> (%o2)                   --- - ------------------------
>                          c                2
>                                          c
> (%i3)               EV(%, a = 1, b = F10, c = - 1, d = F10)
> (%o3)                      - x - 2 F10 LOG(F10 - x)
>                                                         x + F10
> (%i4)                        INTEGRATE(- - - - - - - , x)
>                                                          F10 - x
> (%o4)                      - 2 F10 LOG(x - F10) - x
> 
> May be I am overlooking some details or is it simple an error?
> 
> Klaus
> 
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