=3/2+1/2=21、log4 8=log2² 2³=3/2 log1/9 3=log3^(-2) 3=-1/22、换底公式 log4 8=lg8/lg4 =3lg2/(2lg2)=3/2 log1/9 3=lg3/log1/9=lg3/(-2lg3)=-1/2
