log(2/3)(3/2)=-1,
log(1/4)(3)=lg3/lg(1/4)
=lg3/(-lg4)
=-lg3/lg4,
log(3)(4)=lg4/lg3.
log(3)(5)=lg5/lg3.
log(1/4)(2)=lg2/lg(1/4)
=lg2/(-2lg2)
=-2.
因为 0