True or False

If a logarithm is written without a base it is a natural logarithm.

The answer is: False.

If a logarithm is written without a base it IS NOT a natural logarithm.

The explanation is shown below:

1. I f a logarithm is written without a base, you must assume the base is 10. It is written as below:

log (x)

2. It is important to know that the base a natural logarithm is the irrational number e. It is written as below:

ln (x)