 b \sin \psi \right) {\bf j}. 
% \end{eqnarray}
% </p>
% </html>

% CG position
PTO_t = [x_t y_t 0];                                            % P_{T/O}

% Relative positions
PFT_t = [ a*cos(PSI_t)  a*sin(PSI_t) 0];                        % P_{F/T}
PRT_t = [-b*cos(PSI_t) -b*sin(PSI_t) 0];                        % P_{R/T}

% Axle position
PFO_t = PFT_t + PTO_t;                                          % P_{F/O}
PRO_t = PRT_t + PTO_t ;                                         % P_{R/O}

PFO   = subs(PFO_t,sym