(5)y=2xcos x-3xlog2 014x;
(6)y=.
解:(1)法一:y′=(2x2+3)′(3x-1)+(2x2+3)(3x-1)′
=4x(3x-1)+3(2x2+3)=18x2-4x+9.
法二:∵y=(2x2+3)(3x-1)=6x3-2x2+9x-3,
∴y′=(6x3-2x2+9x-3)′=18x2-4x+9.
(2)∵y=(-2)2=x-4+4,
∴y′=x′-(4)′+4′=1-4·x-=1-2x-.
(3)∵y=x-sincos=x-sin x,
∴y′=x′-(sin x)′=1-cos x.
(4)y′=
=
=.
(5)y′=(2x)′cos x+(cos x)′2x-3[x′log2 014x+(log2 014x)′x]
=2xln 2·cos x-sin x·2x-3[log2 014x+(log2 014e)x]
=2xln 2·cos x-2xsin x-3log2 014x-3log2 104e.
(6)y==cos x-sin x,
∴y′=-sin x-cos x.
8.求过点(1,-1)的曲线y=x3-2x的切线方程.
解:设P(x0,y0)为切点,
则切线的斜率为k=f′(x0)=3x-2,
故切线方程为y-y0=(3x-2)(x-x0),
即y-(x-2x0)=(3x-2)(x-x0),
又知切线过点(1,-1),代入上述方程,
得-1-(x-2x0)=(3x-2)(1-x0),
解得x0=1或x0=-,
故所求的切线方程为y+1=x-1或y-=-(x+),
即x-y-2=0或5x+4y-1=0.
[能力提升]
1.若函数f(x)=x3-f′(-1)·x2+x+5,则f′(1)=________.