The formula is just like this. I don't quite understand the usage of the notion "/". It seems that "/" usually be used in dummy variables. But I am not sure about its usage.The formula is just like this. I don't quite un
The formula is just like this. I don't quite understand the usage of the notion "/". It seems that "/" usually be used in dummy variables. But I am not sure about its usage.The formula is just like this. I don't quite un