I want add to my regression additional features to complicate my model and lower bias, after searching around internet is seems a good idea is to add square features, that can help regression learn in coefficients more knowledge.
I want add to my regression model square of pairs of features $x * y$, i think that can help learn my model relationships between features variables that can be highly correlated.
Problem is when I see at interpretation of $x * y$ it seems incorrect, when i get $high * high = higher$ ex. $5 * 5 = 25$ that is good, but $low * low = higher$ seems strongly invalid ex. $-5 * -5 = 25$, should be $-25$ for my problem statement.
Same problems I have for $high * low = low$, ex. $5 * -5 = -25$, i think should be somewhere between $<-5; 5>$, for example in $0$.
That anyone have any thoughts about what equation I can use to get correct representation?
I will appreciate other ideas for new virtual calculated features.