what is the relationship of the main effects of a linear interaction in regression when to use quadratic terms in regression what is the relationship between the quadratic terms and the linear terms which relationship is most likely to occur between the quadratic interactions of the two continuous variables? what terms do you use to test interaction in regression how to measure quadratic interaction why are quadratic interactions used in regression why do you test for interaction of quadratic terms in regression how to fit a regression model why can't you test interactions between the quadratic terms what order interaction is the quadratic interaction how to test the relationship between quadratic and quadratic terms what is an interaction between quadratic terms what is the importance of a quadratic interaction which of the following quadratic terms is associated with an interaction? what is the main effect of the quadratic term what is the relationship between quadratic terms and first order interactions what is the relationship of quadratic and quadratic terms? why can't i test a quadratic interaction with a quadratic model what is the equation for a quadratic interaction