求值:log2 (5/56)^(1/2)+log2 (14)-(1/2)log2 (35)=log2中2为底数=1/2[-2log2 (7)-3]+log2 (2)+log2 (7) 中的1/2[-2log2 (7)-3]是怎么得到的?

问题描述:

求值:log2 (5/56)^(1/2)+log2 (14)-(1/2)log2 (35)=
log2中2为底数
=1/2[-2log2 (7)-3]+log2 (2)+log2 (7) 中的1/2[-2log2 (7)-3]是怎么得到的?

mi

log2 (5/56)^(1/2)+log2 (14)-(1/2)log2 (35)
=-1/2

既然问道我了,就再写详细些:=1/2(log2 [7^(-2)*2^(-3)]+log2(2*7) =1/2[(log2 7^(-2)+log2 2^(-3)]+log2 (2*7)=1/2log2 7^(-2)+1/2log2 2^(-3)]+log2 (2*7)=1/2*2*log2 7+1/2*(-3)log2 2+log2 (2*7)=1/2[-2log2 (7)...