由参数方程x=t^2/2.y=1-t,所确定的函数的导数d^2y/dx^2,

Question

由参数方程x=t^2/2.y=1-t,所确定的函数的导数d^2y/dx^2,

Answer 1

dx/dt=t
dy/dt=-1
dy/dx=y'=(dy/dt)/(dx/dt)=-1/t
dy'/dt=1/t^2
d^2y/dx^2=y"=(dy'/dt)/(dx/dt)=1/t^3