问题描述: 已知lg2=0.3010,log3=0.4771,求lg根号45 1个回答 分类:数学 2014-10-26 问题解答: 我来补答 lg√45 =1/2lg5*9 =1/2(lg5+2lg3) =1/2(1-lg2+2lg3) =0.5(1-0.3010+0.9542) =0.8266 lg2 +lg5 =lg10 =1 因为lg2=0.3010 所以 lg5=0.699 因为lg根号45 =0.5 (lg5 + 2lg3) =0.5(0.699 +2 *0.4771) =0.8266 展开全文阅读