partial q_3} &=& \frac{\partial {\bf p}_{{\rm R}/{\rm O}}}{\partial \psi} = b \sin \psi {\bf i} - b \cos \psi {\bf j}
%     \end{eqnarray}
% </p>
% </html>

% Generalized forces
Q1 = FF*diff(PFO,x)'    + FR*diff(PRO,x)'    ;
Q2 = FF*diff(PFO,y)'    + FR*diff(PRO,y)'    ;
Q3 = FF*diff(PFO,PSI).' + FR*diff(PRO,PSI).' ;

%%
% <html>
% <p>Substituting equations</p>
% <p>
%     \begin{eqnarray}
%     \nonumber Q_1 &=& F_{x,{\rm F}} \cos \left( \psi + \delta_{\rm F} \right) - F_{y,{\rm F}} \sin \left( \psi + \del