Do I need to know how all these function and memories them all?

Question

There are a lots operator in this link. For better programming, is it necessary to memories them all?
https://www.w3schools.com/java/java_math.asp

Answer 1

You may not need to remember them all, but it may be helpful if you know, what there is, someday you need some of those functions and remember that there was a list, where you can refer those.

Answer 2

//Better if you remember, in some cases you have to use some commons one too

Answer 3

No. Just learn the most common and useful ones.