计算1.2log以5为底10+log以5为底0.25 2.已知lg2=0.3010,lg3=0.4771,求lg根号下45

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计算1.2log以5为底10+log以5为底0.25 2.已知lg2=0.3010,lg3=0.4771,求lg根号下45

计算1.2log以5为底10+log以5为底0.25 2.已知lg2=0.3010,lg3=0.4771,求lg根号下45
计算1.2log以5为底10+log以5为底0.25 2.已知lg2=0.3010,lg3=0.4771,求lg根号下45

计算1.2log以5为底10+log以5为底0.25 2.已知lg2=0.3010,lg3=0.4771,求lg根号下45
2log以5为底10+log以5为底0.25 =log5(100*0.25)=2
lg45=lg9*5=2lg3*lg52=2lg3(1-lg2)= 0.6670

1. 2log以5为底10+log以5为底0.25
=log以5为底100+log以5为底0.25
=log以5为底25
=2
2. lg根号下45
=(lg45)/2
=(lg5+lg9)/2
=(1-lg2+2lg3)/2
=(1-0.3010+2×0.4771)/2
=0.9971