### Logarithm properties : Proof: log_a (B) = (log_x (B))/(log_x (A))

##### By: Sal Khan

Proof of the logarithm property log_a (B) = (log_x (B))/(log_x (A))

Log-a-what? No, this tutorial is about neither chopped wood nor music (actually logarithms do have applications in music), but it is fascinating nonetheless. You know how to take an exponent. Now you can think about what exponent you have to raise a numbe