Years ago, when I was taught about the function lnln (logarithm in base ee), all of my teachers and our book, too, insisted that we should write input of this function inside the absolute value notation and I am doing this since now. But, now when I am reading some university books or some answers on this site, I see in most answers, people write ln(x)ln(x) using parentheses. It's been a question for a long time to me why people just use parentheses instead and how it is not wrong conventionally? I am sure if I used ln(x)ln(x) in high school, it would've always been possible to get a minus point! I am a university student now. Can I write ln(x)ln(x) safely and is it conventionally acceptable in mathematics? (I mean, in general, for ln(f(x))ln(f(x)) not only ln(x)ln(x))
