题目

y=f(x^2),d^2y/dx^2=( )

提问时间：2021-03-20

答案

y = f(x²)
dy/dx = 2xf'(x²)
d²y/dx² = 2[f'(x²)*1 + x * 2xf''(x²)]
= 2f'(x²) + 4x²f''(x²)