wxMaxima 0.8.2 http://wxmaxima.sourceforge.net
Maxima 5.18.1 http://maxima.sourceforge.net
Using Lisp CLISP 2.46 (2008-07-02)
Distributed under the GNU Public License. See the file COPYING.
Dedicated to the memory of William Schelter.
The function bug_report() provides bug reporting information.

(%i29) a:2*%pi ; b:-1 ;
sin(a*x)*exp(b*x^2)+sin(a*(x-1))*exp(b*(x-1)^2)+sin(a*(x+1))*exp(b*(x+1)^2) ;
wxplot2d([sin(a*x)*exp(b*x^2)+sin(a*(x-1))*exp(b*(x-1)^2)+sin(a*(x+1))*exp(b*(x+1)^2),
diff(sin(a*x)*exp(b*x^2)+sin(a*(x-1))*exp(b*(x-1)^2)+sin(a*(x+1))*exp(b*(x+1)^2),x)],
  [x,-5,5]);