设z=sin(x<sup>2</sup>-y<sup>2</sup>),则&#8706;<sup>2</sup>z/&#8706;x<sup>2</sup>=()

题目类型: 单选题

题目内容

设z=sin(x2-y2),则∂2z/∂x2=()

题目选项

A. -sin(x2-y2)
B. sin(x2-y2)
C. -4x2sin(x2-y2)
D. -4x2sin(x2-y2)+2cos(x2-y2)

正确答案

D

题目解析

∂z/∂x=2xcos(x2-y2),∂2z/∂x2=2cos(x2-y2)-4x2sin(x2-y2).

题目纠错