Question

求f[x]=[3+lnx]/x的导数

如题

Answer 1

导数为
[1/x*x-(3+lnx)*1]/x^2
=(-2-lnx)/x^2

Answer 2

f(x)=(3+lnx)/x
f′(x)=[(3+lnx)′x-(3+lnx)x′]/x²
=[(1/x)x-(3+lnx)]/x²
=(1-3-lnx)/x²
=-(2+lnx)/x²