How do you calculate log_6 5log65 with a calculator?
1 Answer
Aug 12, 2016
Explanation:
Use the change of base formula:
log_a b = (log_c b) / (log_c a)logab=logcblogca
So you can use natural or common logs:
log_6 5 = ln 5 / ln 6log65=ln5ln6
log_6 5 = log 5 / log 6log65=log5log6
In fact, if you know
log_6 5 = log 5 / log 6 = (log 10 - log 2) / (log 2 + log 3)log65=log5log6=log10−log2log2+log3
~~ (1-0.30103)/(0.30103+0.47712) = 0.69897/0.77815 ~~ 0.89825≈1−0.301030.30103+0.47712=0.698970.77815≈0.89825
Actually the true value is closer to