How log(N) for binary search

#1

In this lecture he said taking log on both sides but eventually took log on LHS not on RHS can u pls elaborate more on this ?

#2

hi @kartikey.rajput0071 yeah he should have taken
log(2^k) = log n
k log 2 = log n
k = log n
as log 2 = 1 (base is 2)