function y=linode1(p,q)
% - revision feb 12 2004(RMM)
% - Linear nonhomogeneous  first order ode
% - usage y=linode1(p,q)  to solve  y'+p y =q.
% - some authors like to call the integrating factor a source or Green function.
      syms x u yh yp y c f 
      disp(' you are solving  yprime+py=q')
      disp(' where p = '); disp(p)
      disp(' and, where q = '); disp(q)      
      disp('Integrating Factor u= exp(int(p),x)') 
      u=simplify(exp(int(p,'x')))
      disp(' Homogeneous solution is  yh=c/u')
      
      yh=c/u
      
      disp(' The Particular solution is yp=1/u * Int( u*q)')
      
      yp=simplify(int(u*q,'x')/u)
      
      disp(' The general  solution is y = yh+yp')
      
      
      y=simplify(yh+yp)
      disp(' compare with output from the  dsolve routine in matlab')
      dsolve('Df=p*f+q','x')  
     
      return