Is ln equal to log? - Answers

Most people do not mean the same thing when they write "ln" and "log". Both refer to a logarithm, but the base for "ln" is the number e (a special number roughly equal to 2.1781) while the base for "log" is 10, unless otherwise specified. "ln" is called the natural logarithm and "log" is called the common logarithm when it refers to the base 10 logarithm.A quick example of how they are different:log 10,000 = 4ln 10,000 = 9.21The reason for this is that the logarithm is the inverse of (that is, it undoes) exponentiation. The first example asks "what power do I have to raise 10 to in order to get 10,000?" The exponentiation related to the first example is 104 = 10,000. The second example asks "what power do I have to raise e to in order to get 10,000?" The exponentiation related to it is e9.21 = 10,000.