dy/dx=(dy/dt)/(dx/dt)=(cost-tsint)/(1-sint-tcost)d^2y/dx^2=(dy/dx)/(dx/dt)=[(-sint-sint-tcost)(1-sint-tcost)-(cost-tsint)(-cost-cost+tsint)/(1-sint-tcost)^3=[(2sint+tcost)(sint+tcost-1)+(cost-tsint)(2...