# [Maxima] New Maxima user has problem

dlakelan dlakelan at street-artists.org
Thu Mar 13 21:59:02 CDT 2008

```Bob Baker wrote:
> I too was impressed by what Mathematica could do and looked into getting
> it.  I gave up when I learned they will not sell the student version to
> a retired electrical engineer pursuing math studies as a hobby.  Next
> year I could get the professional version with a senior discount, but
> even 50% off is too steep for me.

You might look into taking a class at a local junior college. usually
that will qualify you as a student. However, I'd prefer to sell you on
maxima's ability to do a lot of useful stuff. so maybe we can figure out
how to make maxima do this calculation by fixing some bugs.

i dropped into the debugger when I got the "too many contexts" error,
and got the following output:

invalid array index 51 for #((*GC NIL DATA NIL CMARK 0 SUBC (\$INITIAL))
(*GC NIL SUBC
((*GC NIL DATA NIL CMARK 0 SUBC
(\$INITIAL))))
(*GC NIL SUBC
((*GC NIL SUBC
((*GC NIL DATA NIL CMARK 0 SUBC
(\$INITIAL))))))

..... several pages

...

(\$INITIAL)))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))))
(should be nonnegative and <51)

Perhaps from this error, someone who knows maxima internals can figure
out what maxima has done wrong. clearly it's created some infinite loop
or something...

Also, by performing the transformations mentioned by others I found that
the integrand is the same as:

(cos(5 x) + sqrt(cos(2 x) - 8 cos(x) + 7)
(sqrt(2) cos(4 x) - 4 sqrt(2) cos(3 x) + sqrt(2) cos(2 x) + 2 sqrt(2))
- 8 cos(4 x) + 14 cos(3 x) - 8 cos(2 x) + cos(x))
/(2 cos(2 x) - 16 cos(x) + 14)

the procedure:
ratsimp(trigreduce(subst(lambda([s], ''(exponentialize(sinh('s)))),
sinh, integrand(1,3))));

however, maxima still can't integrate this.

```