问题
选择题
函数y=x2cosx的导数为( )
A.y′=2xcosx-x2sinx
B.y′=2xcosx+x2sinx
C.y′=x2cosx-2xsinx
D.y′=xcosx-x2sinx
答案
y′=(x2)′cosx+x2(cosx)′=2xcosx-x2sinx
故选A
函数y=x2cosx的导数为( )
A.y′=2xcosx-x2sinx
B.y′=2xcosx+x2sinx
C.y′=x2cosx-2xsinx
D.y′=xcosx-x2sinx
y′=(x2)′cosx+x2(cosx)′=2xcosx-x2sinx
故选A