Question

Given log 2 = a, log 3 = b, express the following in terms of a or b or both.

log 1.2

Answer 1

We are given:

• log 2 = a
• log 3 = b

We need to express:

log 1.2

Step 1: Express 1.2 as a fraction

`1.2 = 6/5`

So:

`log 1.2 = log(6/5) = log 6 - log 5`

Now express log 6 using known logs:

log 6 = log (2 · 3) = log 2 + log 3 = a + b

So:

log 1.2 = (a + b) – log 5