50.巨额收益(求推荐票啊！求收藏啊！)
br />
你看你这个，很简单：
dy/dx=(dy/dt)*(dt/dx)=1/e^t*(dy/dt)
d^2y/dx^2={d[1/e^t*(dy/dt)]/dt}*(dt/dx)
=(1/e^t)*(d^2y/dt^2-dy/dt)*(1/e^t)
=(1/e^t)^2*(d^2y/dt^2-dy/dt)
d^3y/dx^3={d[(1/e^t)^2*(d^2y/dt^2-dy/dt)]/dt}*(dt/dx)
=[(1/e^t)^2*(d^3y/dt^3-d^2y/dt^2)-2(1/e^t)^2*(d^2y/dt^2-dy/dt)]*(1/e^t)
=(1/e^t)^3*(d^3y/dt^3-3d^2y/dt^2 2dy/dt)
......
你看你这个，很简单：
dy/dx=(dy/dt)*(dt/dx)=1/e^t*(dy/dt)
d^2y/dx^2={d[1/e^t*(dy/dt)]/dt}*(dt/dx)
=(1/e^t)*(d^2y/dt^2-dy/dt)*(1/e^t)
=(1/e^t)^2*(d^2y/dt^2-dy/dt)
d^3y/dx^3={d[(1/e^t)^2*(d^2y/dt^2-dy/dt)]/dt}*(dt/dx)
=[(1/e^t)^2*(d^3y/dt^3-d^2y/dt^2)-2(1/e^t)^2*(d^2y/dt^2-dy/dt)]*(1/e^t)
=(1/e^t)^3*(d^3y/dt^3-3d^2y/dt^2 2dy/dt)
......