证:lg((a b)/2) lg((b c)/2) lg((c a)/2〉lga lgb lgca,b,c是不全相等的正数

lg(a b) = lg a lg -lg(a+b)=lg(a-b). 证:lg(a+b/2)+lg(b+c/2)+lg(c+a/2)>lga+lgb+lgc,abc不全相等 lg(a+b)/2+lg(b+c)/2+lg(a+c)/2>lga+lgb+lgc 求证lg(a+b)/2+lg(b+c)/2+lg(c+a)/2>lga+lgb+lgc lg(|A|+|B|)/2≥lg(|A|+lg|B|)/2(AB≠0) 求证：lg(|A|+|B|)/2≥lg(|A|+lg|B|)/2(AB≠0) 求证：lg(|A|+|B|)/2≥(lg|A|+lg|B|)/2 (AB≠0) 求证：lg (|A|+|B|)/2>=（lg|A|+lg|B|）/2 lg 2=a lg 3=b.lg 2=a lg 3=b 表示 log 5 lg[a^lga)+lg(b^lgb)+lg(c^lgc)为什么等于lg²a+lg²b+lg²c 已知log14 7=a,log14 5=b,求log35 28(用a,b表示)log 14 7 = lg 7 / lg 14 log 14 5 = lg 5 / lg 14 A = lg 7 / lg 14 = lg 7 / (lg 7 + lg 2) B = lg 5 / lg 14 = (1 - lg2) / (lg 7 + lg 2) 通过以上两式可得:lg 7 = A / (1 - A + B) lg 2 = (1 - A) / ( Lg(a)+Lg(b)=2Lg(a-2b).求Log(4)a/b的值. 证:lg((a b)/2) lg((b c)/2) lg((c a)/2〉lga lgb lgca,b,c是不全相等的正数 lg(a-b)=?lg(a+b)=? lg(a+b)与lg(a-b)的关系 lg(a-b)怎么打开 求证:lg(ㄧAㄧ+ㄧBㄧ/2)>(lgㄧAㄧ+lgㄧBㄧ)/2