Math Help - Log problem

1. Log problem

I have to evaluate

Log1745.3 to four decimal places

I don't know how

2. Log 45.3
---------- = 1.3459
Log 17

to four decimal places

3. Originally Posted by Biddyboots
I have to evaluate

Log1745.3 to four decimal places

I don't know how
use the change of base formula and a calculator

$\log_ab=\frac{\log(b)}{\log(a)}$

so for yours

$\log_{17}45.3=\frac{\log(45.3)}{\log(17)}=\frac{1. 65609}{1.23044} \approx 1.34593$