# [Maxima] factor/simplification problem

Viktor T. Toth vttoth at vttoth.com
Tue May 15 17:33:57 CDT 2007

```Ryan,

I don't think that the expression you expect to see is a correct
simplification of your original expression. They certainly evaluate to
different numerical values:

(%i1)
test:(L^3*(cos(beta)*sinh(beta)*L*c*s-cosh(beta)*sin(beta)*L*c*s+cos(beta)*s
inh(beta)*L*k-cosh(beta)*sin(beta)*L*k-2*beta*sin(beta)*sinh(beta)*EI))/(bet
a^3*EI*(cos(beta)*cosh(beta)*L*c*s+L*c*s+cos(beta)*cosh(beta)*L*k+L*k+beta*c
os(beta)*sinh(beta)*EI-beta*cosh(beta)*sin(beta)*EI))\$
(%i2) test,beta=%pi/4,L=1,c=1,s=1,k=1,EI=1\$
(%i3) %,numer;
(%o3) 			      - 0.91779016483503
(%i4) test2:cos(beta)*cosh(beta)*L*(c*s+k)\$
(%i5) test2,beta=%pi/4,L=1,c=1,s=1,k=1,EI=1\$
(%i6) %,numer;
(%o6) 			       1.87328013886286

Generally, your friends in this case would be trigsimp, factor, expand,
trigexpand and trigreduce (to name a few), but of course, Maxima will not
produce a result (or so we hope!) that is mathematically not correct.

Viktor

-----Original Message-----
From: maxima-bounces at math.utexas.edu [mailto:maxima-bounces at math.utexas.edu]
On Behalf Of Ryan Krauss
Sent: Tuesday, May 15, 2007 5:36 PM
To: maxima list
Subject: [Maxima] factor/simplification problem

I have this expression
test:(L^3*(cos(beta)*sinh(beta)*L*c*s-cosh(beta)*sin(beta)*L*c*s+cos(beta)*s
inh(beta)*L*k-cosh(beta)*sin(beta)*L*k-2*beta*sin(beta)*sinh(beta)*EI))/(bet
a^3*EI*(cos(beta)*cosh(beta)*L*c*s+L*c*s+cos(beta)*cosh(beta)*L*k+L*k+beta*c
os(beta)*sinh(beta)*EI-beta*cosh(beta)*sin(beta)*EI))

and it has terms in the denominator like
cos(beta)*cosh(beta)*L*c*s+cos(beta)*cosh(beta)*L*k

I don't seem to be able to make Maxima factor/simplify this as
cos(beta)*cosh(beta)*L*(c*s+k)

which I would prefer.  My knowledge of Maxima simplification is not
all that great, but poking around in the manual and searching the help