已知lg2≈0.3010,lg3≈0.4771,求下列各式的值(结果保留4位小数)(1)lg54(2)lg1.5(3)lg4/9(4)lg45要具体过程
问题描述:
已知lg2≈0.3010,lg3≈0.4771,求下列各式的值(结果保留4位小数)(1)lg54(2)lg1.5(3)lg4/9(4)lg45要具体过程
答
(1) lg54 = lg2 + 3*lg3 = …
(2) lg1.5 = lg3 - lg2= …
(3) lg4/9 = 2*(lg2 - lg3) = …
(4) lg45 = lg(10*9/2) = 1 + 2*lg3 - lg2 = …