Logarithm Formulas
Logarithm Formulas
[ ‘a > 0’, ‘b > 0’ and ‘m ∈ N’ ]
1. If am = b, then we can write it as ‘logₐb = m‘ (read it as ‘the value of logarithm of b with respect to base a is m‘)
2. If logₐb = m , then we can write it as am = b
3. log (a × b) = log(a) + log(b)
4. log (a ÷ b) = log(a) – log(b)
5. log(am) = mlog(a)
6. log(1) = 0
7. logab = log(b)/log(a) = 1/logba
8. alogab = b
9. log(1/a) = – log(a)
10. logaa = 1
Note: If base of the logarithm is the number 10 then it is called “Basic/Common Logarithm” and if base of the logarithm is the number e (≈2.718) ,then it is called “Natural Logarithm“