x: Ax * (6*((t-t0)/D)^5 - 15*((t-t0)/D)^4 + 10*((t-t0)/D)^3);
y: Ay * (6*((t-t0)/D)^5 - 15*((t-t0)/D)^4 + 10*((t-t0)/D)^3);

xdot: diff(x,t);
ydot: diff(y,t);

D_tang: sqrt((Ax/D)^2 + (Ay/D)^2);
Vtang : D_tang * ((30*(t-t0)^2)/D^2-(60*(t-t0)^3)/D^3+(30*(t-t0)^4)/D^4);

/* Gradient (partial derivatives) of xdot */
diff(xdot,t0);
diff(xdot,D);
diff(xdot,Ax);
diff(xdot,Ay);

/* Gradient (partial derivatives) of ydot */
diff(ydot,t0);
diff(ydot,D);
diff(ydot,Ax);
diff(ydot,Ay);

/* Gradient (partial derivatives) of Vtang */
diff(Vtang,t0);
algebraic: true;
diff(Vtang,D);
diff(Vtang,Ax);
diff(Vtang,Ay);

/* Hessian (second-order partial) of xdot */

/* first column */
diff(diff(xdot,t0),t0);
diff(diff(xdot,t0),D);
diff(diff(xdot,t0),Ax);
diff(diff(xdot,t0),Ay);

/* Hessian (second-order partial) of xdot */

/* second column */
diff(diff(xdot,D),t0);
diff(diff(xdot,D),D);
diff(diff(xdot,D),Ax);
diff(diff(xdot,D),Ay);

/* Hessian (second-order partial) of xdot */

/* third column */
diff(diff(xdot,Ax),t0);
diff(diff(xdot,Ax),D);
diff(diff(xdot,Ax),Ax);
diff(diff(xdot,Ax),Ay);

/* Hessian (second-order partial) of xdot */

/* fourth column */
diff(diff(xdot,Ay),t0);
diff(diff(xdot,Ay),D);
diff(diff(xdot,Ay),Ax);
diff(diff(xdot,Ay),Ay);

/* Hessian (second-order partial) of ydot */

/* first column */
diff(diff(ydot,t0),t0);
diff(diff(ydot,t0),D);
diff(diff(ydot,t0),Ax);
diff(diff(ydot,t0),Ay);

/* Hessian (second-order partial) of ydot */

/* second column */
diff(diff(ydot,D),t0);
diff(diff(ydot,D),D);
diff(diff(ydot,D),Ax);
diff(diff(ydot,D),Ay);

/* Hessian (second-order partial) of ydot */

/* third column */
diff(diff(ydot,Ax),t0);
diff(diff(ydot,Ax),D);
diff(diff(ydot,Ax),Ax);
diff(diff(ydot,Ax),Ay);

/* Hessian (second-order partial) of ydot */

/* fourth column */
diff(diff(ydot,Ay),t0);
diff(diff(ydot,Ay),D);
diff(diff(ydot,Ay),Ax);
diff(diff(ydot,Ay),Ay);

/* Hessian (second-order partial) of Vtang */

/* first column */
diff(diff(Vtang,t0),t0);
diff(diff(Vtang,t0),D);
diff(diff(Vtang,t0),Ax);
diff(diff(Vtang,t0),Ay);

/* Hessian (second-order partial) of Vtang */

/* second column */
diff(diff(Vtang,D),t0);
diff(diff(Vtang,D),D);
diff(diff(Vtang,D),Ax);
diff(diff(Vtang,D),Ay);

/* Hessian (second-order partial) of Vtang */

/* third column */
diff(diff(Vtang,Ax),t0);
diff(diff(Vtang,Ax),D);
diff(diff(Vtang,Ax),Ax);
diff(diff(Vtang,Ax),Ay);

/* Hessian (second-order partial) of Vtang */

/* fourth column */
diff(diff(Vtang,Ay),t0);
diff(diff(Vtang,Ay),D);
diff(diff(Vtang,Ay),Ax);
diff(diff(Vtang,Ay),Ay);