若f''(x)存在,且y=f（x^2）,求(d^2y)/(dx^2)

若f''(x)存在,且y=f（x^2）,求(d^2y)/(dx^2)
若f''(x)存在,且y=f（x^2）,求(d^2y)/(dx^2)

若f''(x)存在,且y=f（x^2）,求(d^2y)/(dx^2)
dy/dx = 2xf'(x^2)
d^2y/dx^2 = d(2xf'(x^2))/dx = 2f'(x^2) + 4x^2f''(x^2)
这些都是套用复合函数导数公式而已,lz应该能自己搞出来