I have two values Time taken and Energy consumed. When time taken goes up energy also goes up. Similarly when time goes down energy consumed also goes down. However, the change in both values is not by the constant factor.
I want to form some relation between values of time and energy. Only thing comes to my mind is approximately directly proportional. Is there any symbol for that? I have not found any evidence of such symbol. Closest thing I have come to is that similar Thread. But it does not provide any validity for such approximately directly proportional relation.