LOGARITHMS 3

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

solution

= log 400,000

=log(100,000 x 4)

=log100,000 + log4

=log10⁵ + log2²

=5log10 + 2log2

=(5x1) + 2(0.3010)

=5– 2(0.3010)

=5 – 0.6020

=4.398

Hence log2500=3.398

TRY THIS……………

If log 2= 0.3010; find the value of log 80,000 without using tables.