求下列函数的导数:(1)y=log 4 x 3 -log 4 x 2 ;(2)y= 2 x 2 +1 x

2025-01-02 10:27:49
推荐回答(1个)
回答1:

(1)∵y= lo g 4 x 3 -lo g 4 x 2 =log 4 x,
∴y′= (lo g 4 x ) =
1
xln4

(2)∵y=
2 x 2 +1
x
-2x
=2x+
1
x
-2x=
1
x

∴y′=(
1
x
)′=-
1
x 2

(3)∵y=-2sin
x
2
(2sin 2
x
4
-1)=2sin
x
2
(1-2sin 2
x
4

=2sin
x
2
cos
x
2
=sinx.
∴y′=(sin x)′=cos x.