LOGARITHMS 3

If log 2= 0.3010; find the value of log 400,000 without using tables.

solution

=log200,000

=log(4 x 100,000)

=log4 + log100,000

=log2² + log10⁵

=2log2 + 5log10

=2(0.3010) + (5 x 1)  [since log10=1 and Log3=0.3010]

=(0.6020) +  5

=5.6020

Hence log400,000=5.6020

TRY THIS……………

If log 2= 0.3010; find the value of log 4,000,000 without using tables.