Laws of logarithms
Multiplication: |
log(n*m) = log(n) + log(m) |
thus log(2*3) = log(2) + log(3) |
Division: |
log(n/m) = log(n) - log(m) |
thus log(2/3) = log(2) - log(3) |
Raising to a power: |
log(nm) = m * log(n) |
thus log(23) = 3 * log(2) |
ln(exp(n)) = n |
thus ln(exp(2)) = 2 |
Changing the base of a logarithm
If instead of calculating 10log (a), you wish to calculate blog(a), divide the logarithm of a by the logarithm of b:
blog (a) = 10log (a) / 10log( b )
See also: