Question

Diketahui log 2=0,3010. Log 3= 0,4771. Log 7=0,8451.
nyatakan logaritma berikut dalam bentuk persamaan logaritma yang ada diatas.
1. Log 0,48
2. Log 75

Answer 1

Log 0,48 = log (48/100)
= log 48 - log 100
= (log 2^4 x 3) - log (10^2)
= 4 log2 + log 3 - 2 log10
= 4 (0,3010) + 0,4771 - 2
= 1,2040 + 0,4771 - 2
= 1,6811 - 2
= - 0,3189


log 75
= log (3 x 5^2)
= log 3 + 2 log 5
= log 3 + 2 log(10/2)
= log 3 + 2 (log 10 - log 2)
= 0,4771 + 2 (1 - 0,3010)
= 0,4771 + 2 ( 0,6990)
= 0,4771 +  1,3980
= 1,8751