Question

Considerando log2 = 6, log 3 = 5 e Log 5 = 7 determine o valor de:

a) log 15
b) log 30
c)log 45
d) log 1,2

Answer 1

Vamos à resolução dos itens propostos.

Letra a):

log(15) = log(3.5) = log(3)+log(5) = 5+7 = 12

Letra b):

log(30) = log(6.5) = log(6)+log(5) = log(2.3)+log(5) = log(2)+log(3)+log(5) = 6+5+7 = 18

Letra c):

log(45) = log(9.5) = log(9)+log(5) = log(3.3)+log(5) = log(3)+log(3)+log(5) = 5+5+7 = 17

Letra d):

log(1,2) = log(12/10) = log(12)-log(10) = log(3.4)-log(10) = log(3)+log(4)-log(10) = log(3)+log(2.2)-log(10) = log(3)+log(2)+log(2)-log(10) =

5+6+6-1 = 16

Abraços!