这个是由定义得到的设x=log2(1/3),则由对数定义得2^x=1/3将x=log2(1/3)代入上面的指数式即得
是的,过程:令log2 (3)=x,2的x次方等于3,2的log2 (3)次方=2的x次方=3
log2(36)-2log2(3)=log2(36)-log2(3^2) =log2(36)-log2(9) =log2(36/9) =log2(4) =log2(2^2) =2log2(2) =2
使用对数的换底公式,logs(N)=logb(N)/logb(a). log4(3)=log2(3)/log2(4)=1/2*log2(3)=log√3 2log2 3+2log4 3=3log2 3
满意答案用换底公式log2^3=lg2/lg3上式等于(lg2/lg3)*(lg3/lg5)*(lg5/lg7)*(lg7/lg8)=lg2/lg8=log2^8=38=2^3log2^8=3log2^2=3
log1/2(2/3) =log1/2(2)-log1/2(3) =-1+lg2(3) =-1+1.585 =0.585
(1/2)^[log2(3)] =[2^(-1)]^[log2(3)] =2^[(-1)*log2(3)] =2^[-log2(3)] =2^[log2(3)^(-1)] =2^[log2(1/3)]
等于负三。
log2 32 =log2 2^5 =5