Question

｛x=e右上角tcost,则 dy/dx = ｛y=e右上角tsint,

Answer 1

dx/dt=e^tsint+e^tcost

dy/dt=e^tcost-e^tsint

dy/dx=dy/dt/(dx/dt)

=(e^tcost-e^tsint)/(e^tsint+e^tcost)

=(cost-sint)/(sint+cost)