Question

log 7 7 , log 2 128, log 10.000

Answer 1

O valor dos logaritmos podem ser determinados utilizando a definição.

$log_{_b}a~=~c~~\longrightarrow~~a~=~b^c$

a)

$log_{_7}7~=~x\\\\\\7~=~7^x\\\\\\7^1~=~7^x\\\\\\\boxed{x~=~1}$

b)

$log_{_2}128~=~y\\\\\\128~=~2^y\\\\\\2^7~=~2^y\\\\\\\boxed{y~=~7}$

c)

$log\,10000~=~z\\\\\\10000~=~10^z\\\\\\10^4~=~10^z\\\\\\\boxed{z~=~4}$