设f(x)具有二阶导数,y=f(x 2 ),则
f´´(4)
16f´´(4)
2f´(4)+16f´´(4)
2f´(4)+4f´´(4)
解析:y´=2xf´(x 2 ),y´´=2f´(x 2 )+4x 2 f´´(x 2 ),