How do you calculate #log_5 (28)# with a calculator?
1 Answer
See explanation.
Explanation:
The given logarythm cannot be calculated because
To do this we have to use the Change of Base Formula, which is:
#log_ax=log_bx/log_ba#
This formula lets us change the logarythm with non standard base to a quotient of logarythms of any other base.
Calculators don't have logarythm of base
The procedure is:

Press
#5# and#log# to calculate#log5# . 
Press
#M# to put the result in memory. 
Press
#28# and#log# to display#log28# 
Press
#:# (division) button 
Press
#RM# to recall the result stored in pt. 2. 
Press
#=# to calculate the final result.