(1)y=x4+3x2-6;
(2)y=6
+2x;(3)y=x(2x-1)(3x+2);
(4)y=xsinx+cosx.
(1)y=x4+3x2-6;
(2)y=6
+2x;(3)y=x(2x-1)(3x+2);
(4)y=xsinx+cosx.
分析：这些函数都是由基本初等函数经过四则运算得到的简单函数，求导时可直接利用求导法则和导数公式进行求导.
解：(1)y′=(x4+3x2-6)′
=(x4)′+(3x2)′-(6)′
=4x3+6x.
(2)y′=(6x
+2x)′=(6x
)′+(2x)′=6×
+4×
x
+2=21x
+2.(3)y′=［x(2x-1)(3x+2)］′
=［x(2x-1)］′(3x+2)+x(2x-1)(3x+2)′
=x′(2x-1)(3x+2)+x(2x-1)′(3x+2)+x(2x-1)(3x+2)′
=(2x-1)(3x+2)+2x(3x+2)+3x(2x-1)
=18x2+2x-2.
(4)y′=(xsinx+cosx)′
=(xsinx)′+(cosx)′
=x′·sinx+(sinx)′·x+(cosx)′
=sinx+xcosx-sinx
=xcosx.