5.2.2 Change of Base of Logarithms May 30, 2020July 20, 2013 by Change of Base of Logarithms log a b= log c b log c a and log a b= 1 log b a Example: Find the value of the following: a. log 25 100 b. log 3 0.45 Answer: (a) log 25 100= log 10 100 log 10 25 = log 10 10 2 log 10 25 = 2 1.3979 =1.431 (b) log 3 0.45= log 10 0.45 log 10 3 = −0.3468 0.4771 =−0.727
a. log 100 should be log 10 to the power of 2, equal 2