derivatives of a parametric equation

[parisse]

Code:


y1:=diff(y,t); x1:=diff(x,t); normal(diff(y1/x1,t)/x1);

Since x1=dx/dt and y1=dy/dt, dy/dx=y1/x1, then d2y/dx^2=d(dy/dx)/dx=d/dt(dy/dx)/x1