Question

Log 2=0,30 e log3=0,48, quanto vale:

Answer 1

a) log20=log(2.10)=log2+log10

log20=0,30+1=1,30.

b) log0,0002=log(2.10⁻⁴)=log2+log10⁻⁴

log0,0002=log2-4log10=0,30-4=-3,70

c) log72= log(24.3)=log (2³. 3²)

log72= 3log2+2log3=3.0,30+2.0,48

log72=0,90+0,96=1,86

d) log500=log(1000/2)=

log500=log1000-log2=3-0,30=2,70

d) log250=log(500/2)=log500-log2

log250=2,70-0,30=2,40.

e)log1,25= log(125.10⁻²)=log125+log10⁻²

log(125.10⁻²) =log(250/2)-2log10

log(125.10⁻²)=log250-log2-2log10

log(125.10⁻²) =2,40-0,30-2=0,40-0,30=0,10

log(1,25)=0,10