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4
2个回答

1.2log以5为底10+log以5为底0.25

=2log以5为底10+2log以5为底0.5

=2log以5为底10×0.5

=2log以5为底5

=2

2.已知lg2=0.3010,lg3=0.4771,

lg根号下45

=lg3+1/2lg5

=lg3+1/2(1-lg2)

=0.4771+1/2×(1-0.3010)

=0.4771+0.3345

=0.8116

3.【(1-log以6为底3)²+log以6为底2*log以6为底18】*log以4为底6

=【log²以6为底2+log以6为底2*(2-log以6为底2)】*log以4为底6

=【log²以6为底2+log以6为底2+log²以6为底2】*log以4为底6

=log以6为底2*log以4为底6

=lg2/lg6*lg6/lg4

=lg2/lg6*lg6/(2lg2)

=1/2