Lets say I have some variable x in a domain i.e. <-inf, inf>. If I want to change it's space I know that I can multiply or divide it by some other number k, i.e. if I want to change it to circular space I can multiply/divide it by 2PI. What is the difference if I multiply it versus if I divide it by some number, what would be the outcome and what are the different uses?
I could take for e.g. time variable t and multiply/divide it by 2PI. Why would I want to do one versus the other besides that one gives smaller resulting values and other one greater values?