Respuesta :

altavistard
take the natural log of both sides:

ln 2^3 = ln 8, or 3 ln 2 = ln 8, following rules of logs.

mathmate
Definition of log:
Log (base b) (x) = y  or equivalently
if b^y = x then Log (base b) (x) = y

Given 2^3=8  
set x=8, b=2, y=3
take log (to base 2) on both sides, then
log(base 2) 8 = 3