设二元函数 z=sin(x2−y2)z=sin(x2−y2), 则 ∂2z∂x2=
A、2cos(x2−y2)−4x2sin(x2−y2)2cos(x2−y2)−4x2sin(x2−y2);
B、sin(x2−y2)sin(x2−y2);
C、−4x2sin(x2−y2);
D、−sin(x2−y2)−sin(x2−y2)
发布时间:2025-05-20 03:29:30
A、2cos(x2−y2)−4x2sin(x2−y2)2cos(x2−y2)−4x2sin(x2−y2);
B、sin(x2−y2)sin(x2−y2);
C、−4x2sin(x2−y2);
D、−sin(x2−y2)−sin(x2−y2)