设y'=p 则y''=p(dp/dy) 怎么推出来的啊
问题描述:
设y'=p 则y''=p(dp/dy) 怎么推出来的啊
答
y'' = d(y')/dx = dp/dx = dp/dy * dy/dx = dp/dy * y' = dp/dy * p = p(dp/dy)
设y'=p 则y''=p(dp/dy) 怎么推出来的啊
y'' = d(y')/dx = dp/dx = dp/dy * dy/dx = dp/dy * y' = dp/dy * p = p(dp/dy)