Log generally refers to a logarithm to the base 10. Ln basically refers to a logarithm to the base e. ... The log function is more widely used in physics when compared to ln. As logarithms are usually taken to the base in physics, ln is used much less.

Should I write log or ln?

Ultimately, of course, it's simply a matter of personal preference. If you're taking a physics exam, do ln(x) if youre taking a math exam do log(x).

Why do people use log instead of ln?

We prefer natural logs (that is, logarithms base e) because, as described above, coefficients on the natural-log scale are directly interpretable as approximate proportional differences: with a coefficient of 0.06, a difference of 1 in x corresponds to an approximate 6% difference in y, and so forth.