设z=(3x2+y2)xy,则等于( ).

admin2021-03-17  22

问题 设z=(3x2+y2)xy,则等于(    ).

选项 A、xy·(3x2+y2)xy-1
B、(3x2+y2)xy·ln(3x2+y2)
C、y·(3x2+y2)xy[(3x2+y2)ln(3x2+y2)+6x2]
D、y·(3x2+y2)xy-1[(3x2+y2)ln(3x2+y2)+6x2]

答案D

解析 因z=(3x2+y2)xy可看作是z=uv,u=3x2+y2,v=xy复合而成,=v·uv-1·6x+uv·lnu·y=xy·(3x2+y2)xy-1·6x+(3x2+y2)xy·ln(3x2+y2)·y=y·(3x2+y2)xy-1·[(3x2+y2)ln(3x2+y2)+6x2].
转载请注明原文地址:https://kaotiyun.com/show/aqCC777K
0

最新回复(0)