> f:= exp(-x^2/2/sigma^2);

                                               2
                                              x
                             f := exp(- 1/2 ------)
                                                 2
                                            sigma
--------------------------------------------------------------------------------
> sigma := 1; g:=f;

                                   sigma := 1

                                               2
                               g := exp(- 1/2 x )
--------------------------------------------------------------------------------
> 
--------------------------------------------------------------------------------
> sigma := 1.5; h:=f;

                                  sigma := 1.5

                                                    2
                           h := exp( - .2222222223 x )
--------------------------------------------------------------------------------
> sigma := 2; k:=f;

                                   sigma := 2

                                               2
                               k := exp(- 1/8 x )
--------------------------------------------------------------------------------
> plot({g,h,k},x=-4..4,title='Gaussians');
--------------------------------------------------------------------------------
> 
