dy/dx=(dy/dt)/(dx/dt)={[8at*(1+t^3)-4at^2*3t^2]/(1+t^3)^2}/{[4a(1+t^3)-4at*3t^2]/(1+t^3)^2}}=(8at-4at^4)/(4a)=2t-t^4d^2y/dx^2=d(dy/dx)/dx=[d(dy/dx)/dt]/[dx/dt]=(2-4t^3)/{[4a(1+t^3)-4at*3t^2]/(1+t^3)^2...