对数的运算 lg22+lg2*lg5+lg5
来源:学生作业帮助网 编辑:作业帮 时间:2024/06/30 06:17:38
![对数的运算 lg22+lg2*lg5+lg5](/uploads/image/z/1143234-18-4.jpg?t=%E5%AF%B9%E6%95%B0%E7%9A%84%E8%BF%90%E7%AE%97+lg22%2Blg2%2Alg5%2Blg5)
对数的运算 lg22+lg2*lg5+lg5
对数的运算 lg22+lg2*lg5+lg5
对数的运算 lg22+lg2*lg5+lg5
应该是(lg2)^2+lg2*lg5+lg5 吧.
(lg2)^2+lg2*lg5+lg5
=(lg2)^2+lg2*lg(10/2)+lg(10/2)
=(lg2)^2+lg2*(lg10-lg2)+lg10-lg2
=(lg2)^2+lg2*(1-lg2)+ 1-lg2
=(lg2)^2 +lg2 -(lg2)^2+ 1-lg2
=1.
如果是lg22……,就得用计算器了.