Possible bug?





-----maxima-bounces at math.utexas.edu wrote: -----


>This is a bug.  Maxima shouldn't be allowing you to differentiate with
>respect to a constant like %pi any more than with respect to an
>expression.
>
>             -s

It's a disaster, but Maxima differentiates with respect to %pi
to simplify trig functions

(%i2) sin(%pi * x);
  1> (SDIFF ((MTIMES SIMP) $%PI $X) $%PI)
    2> (SDIFF $%PI $%PI)
    <2 (SDIFF 1)
    2> (SDIFF $X $%PI)
    <2 (SDIFF 0)
  <1 (SDIFF $X)
(%o2) sin(%pi*x)

The trig simplification functions have some related problems:

Just plain wrong:

  (%i1) sin(%pi + x[%pi]);
  (%o1) 0

Silly inconsistency:

  (%i2) sin(2 * %pi + %pi^2);
  (%o2) sin(%pi^2+2*%pi)

  (%i3) sin(2 * %pi + %e^2);
  (%o3) sin(%e^2)

Barton