根据(lnx)'=1/x
而,log2(x)=lnx/(ln2)
就有:
y'=[log2(x)]'*log4(x)+log2(x)*[(log4(x)]'
=[1/(x*ln2)]*log4(x)+[1/(x*ln4)]*log2(x)
其实结果可以写为:
=[1/(x*ln2)]*lnx/(ln4)+[1/(x*ln4)]*lnx/(ln2)
=[(lnx)/x]*[1/(ln2*ln4)]