how to determine the relationship between age and age when is age squared why do some models include age as an explanatory variable in the model does age squared include the age can we use age squared as explanatory what is the correlation between age and age squared why use age squared when using age as explanatory variable in a regression do you use age and age as explanatory variables when should we use age squared as an explanatory variable why do we use age squared in a model when to use age as explanatory variable why is age squared with age in a regression should age be squared? age and age squared as explanatory factors how do we know age and age is not a supplementary variable for the age square why are age squared do we add age and age as dependent variable age squared in model what is the correlation between the age and the square of age in a logistic regression model?