题目

设f''(u)存在,求下列函数的二阶导数d^2y/dx^2 (1)y=f(x^2) (2)y=
设f''(u)存在,求下列函数的二阶导数d^2y/dx^2
(1)y=f(x^2)
(2)y=f(sinx)

提问时间：2021-01-09

答案

(1)
y = f(x^2)
y' =2xf'(x^2)
y'' =2f'(x^2) + 4x^2.f''(x^2)
(2)
y=f(sinx)
y' = cosxf'(sinx)
y''= -sinxf'(sinx) + (cosx)^2f''(sinx)